Problems using Xdebug in docker context

I use Visual Studio Code with Remote Explorer for the development of a Moodle plug-in inside a custom created Moodle docker container with php 7.4.30. In this context I want to use "Xdebug" together with the VS Plug-in "PHP Debug" (installed in the container context). Unfortunately I can't establish a (solid) working connection between Xdebug and PHP Debug.

Dockerfile:

RUN apt-get install -y \
 php \
 php-pgsql \
 php-curl \
 php-zip \
 php-xml \
 php-mbstring \
 php-soap \
 php-xmlrpc \
 php-intl \
 php-gd \
 php-xdebug \
 libapache2-mod-php

docker-compose:

moodle:
  build: "./moodle"    
  extra_hosts:
    - "host.docker.internal:host-gateway"
  [...]
  ports:
    - "80:80"
    - "443:443"

20-xdebug.ini:

zend_extension=xdebug.so

[XDebug]

xdebug.mode = debug
xdebug.remote_enable = 1
xdebug.idekey = "VSCODE"
xdebug.client_port = 9003
xdebug.remote_autostart = 1
xdebug.start_with_request = yes
xdebug.log=/tmp/xdebug-local.log

launch.json:

{"version": "0.2.0",
    "configurations": [
        {
            "name": "Listen for Xdebug",
            "type": "php",
            "request": "launch",
            "port": 9003,
            "pathMappings": {
                "/var/www/": "${workspaceRoot}/"
            }
        }
     ]
}

php -i returns:

__   __   _      _                 
\ \ / /  | |    | |                
 \ V / __| | ___| |__  _   _  __ _ 
  > < / _` |/ _ \ '_ \| | | |/ _` |
 / . \ (_| |  __/ |_) | |_| | (_| |
/_/ \_\__,_|\___|_.__/ \__,_|\__, |
                              __/ |
                             |___/ 

Version => 3.0.2
Support Xdebug on Patreon, GitHub, or as a business: https://xdebug.org/support

           Enabled Features<br/>(through 'xdebug.mode' setting)           
Feature => Enabled/Disabled
Development Aids => ✘ disabled
Coverage => ✘ disabled
GC Stats => ✘ disabled
Profiler => ✘ disabled
Step Debugger => ✔ enabled
Tracing => ✘ disabled

Debugger => enabled
IDE Key => VSCODE

Directive => Local Value => Master Value
xdebug.auto_trace => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.cli_color => 0 => 0
xdebug.client_discovery_header => no value => no value
xdebug.client_host => localhost => localhost
xdebug.client_port => 9003 => 9003
xdebug.cloud_id => no value => no value
xdebug.collect_assignments => Off => Off
xdebug.collect_includes => (setting removed in Xdebug 3) => (setting removed in Xdebug 3)
xdebug.collect_params => (setting removed in Xdebug 3) => (setting removed in Xdebug 3)
xdebug.collect_return => Off => Off
xdebug.collect_vars => (setting removed in Xdebug 3) => (setting removed in Xdebug 3)
xdebug.connect_timeout_ms => 200 => 200
xdebug.coverage_enable => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.default_enable => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.discover_client_host => Off => Off
xdebug.dump.COOKIE => no value => no value
xdebug.dump.ENV => no value => no value
xdebug.dump.FILES => no value => no value
xdebug.dump.GET => no value => no value
xdebug.dump.POST => no value => no value
xdebug.dump.REQUEST => no value => no value
xdebug.dump.SERVER => no value => no value
xdebug.dump.SESSION => no value => no value
xdebug.dump_globals => On => On
xdebug.dump_once => On => On
xdebug.dump_undefined => Off => Off
xdebug.file_link_format => no value => no value
xdebug.filename_format => no value => no value
xdebug.force_display_errors => Off => Off
xdebug.force_error_reporting => 0 => 0
xdebug.gc_stats_enable => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.gc_stats_output_dir => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.gc_stats_output_name => gcstats.%p => gcstats.%p
xdebug.halt_level => 0 => 0
xdebug.idekey => VSCODE => VSCODE
xdebug.log => /tmp/xdebug-local.log => /tmp/xdebug-local.log
xdebug.log_level => 7 => 7
xdebug.max_nesting_level => 256 => 256
xdebug.max_stack_frames => -1 => -1
xdebug.mode => debug => debug
xdebug.output_dir => /tmp => /tmp
xdebug.overload_var_dump => (setting removed in Xdebug 3) => (setting removed in Xdebug 3)
xdebug.profiler_append => Off => Off
xdebug.profiler_enable => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.profiler_enable_trigger => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.profiler_enable_trigger_value => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.profiler_output_dir => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.profiler_output_name => cachegrind.out.%p => cachegrind.out.%p
xdebug.remote_autostart => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_connect_back => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_enable => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_host => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_log => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_log_level => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_mode => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_port => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.remote_timeout => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.scream => Off => Off
xdebug.show_error_trace => Off => Off
xdebug.show_exception_trace => Off => Off
xdebug.show_local_vars => Off => Off
xdebug.show_mem_delta => (setting removed in Xdebug 3) => (setting removed in Xdebug 3)
xdebug.start_upon_error => default => default
xdebug.start_with_request => default => default
xdebug.trace_enable_trigger => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.trace_enable_trigger_value => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.trace_format => 0 => 0
xdebug.trace_options => 0 => 0
xdebug.trace_output_dir => (setting renamed in Xdebug 3) => (setting renamed in Xdebug 3)
xdebug.trace_output_name => trace.%c => trace.%c
xdebug.trigger_value => no value => no value
xdebug.var_display_max_children => 128 => 128
xdebug.var_display_max_data => 512 => 512
xdebug.var_display_max_depth => 3 => 3

For a very short time, the connection worked. But now when I try to set a breakpoint nothing happens and the console logs:

-> setBreakpointsRequest
{
  command: 'setBreakpoints',
  arguments: {
    source: { name: 'info.php', path: '/var/www/info.php' },
    lines: [ 6 ],
    breakpoints: [ { line: 6 } ],
    sourceModified: false
  },
  type: 'request',
  seq: 13
}
<- setBreakpointsResponse
Response {
  seq: 0,
  type: 'response',
  request_seq: 13,
  command: 'setBreakpoints',
  success: true,
  body: {
    breakpoints: [
      {
        verified: true,
        line: 6,
        source: { name: 'info.php', path: '/var/www/info.php' },
        id: 3
      }
    ]
  }
}

When I try to evaluate a command the console returns:

echo 'test';
-> evaluateRequest
{
  command: 'evaluate',
  arguments: { expression: "echo 'test';", context: 'repl' },
  type: 'request',
  seq: 10
}

<- evaluateResponse
Response {
  seq: 0,
  type: 'response',
  request_seq: 10,
  command: 'evaluate',
  success: false,
  message: 'Cannot evaluate code without a connection'
}

Anyone have an idea what the problem could be?