debugger doesn't stop at breakpoint - using c++ and vscode

I am attempting to debug some c++ code. The debugger wont stop at the breakpoints I have set.

I'm using vscode on ubuntu 20.

The breakpoint is hollow, when hovering it says: "Module containing this breakpoint has not yet loaded or the breakpoint address could not be obtained."

My makefile:

CXX = g++

CXX_FLAGS = -g -Wall -std=c++17

O_FILES = main.o \
            cache.o

TARGET = main

all:            $(TARGET)

$(TARGET):      $(O_FILES)
                    $(CXX) $(CXX_FLAGS) $(O_FILES) -o $@

.phony:         clean

clean:
                    rm -f *~ *.o $(TARGET)

#dependencies
cache.o:    cache.cc cache.hh   

tasks.json I have tried using g++ instead of make setting the appropriate flags as well, which resulted in error.

{
    "tasks": [
        {
            "type": "shell",
            "label": "C/C++: g++ build active file",
            "command": "make",
            "args": [
            ],
            "options": {
                "cwd": "${workspaceFolder}"
            },
            "problemMatcher": [
                "$gcc"
            ],
            "group": {
                "kind": "build",
                "isDefault": true
            }
        }
    ],
    "version": "2.0.0"
}

launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "g++ - Build and debug active file",
            "type": "cppdbg",
            "request": "launch",
            "program": "${fileDirname}/main",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                }
            ],
            "miDebuggerPath": "/usr/bin/gdb"
        }
    ]
}

main:

#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include "cache.hh"

using namespace std;


int main(int argc, char** argv) {
    Cache direct_mapped(8, 1);
    int a;

    cout << direct_mapped.getCacheSize() << endl;
    direct_mapped.updateCacheBlock(1, 5, 31);
    direct_mapped.printCache(1);
    cin >> a;
    return 0;

}

terminal ouput after running 'make':

g++    -c -o main.o main.cc
g++    -c -o cache.o cache.cc
g++ -g -Wall -std=c++17 main.o cache.o -o main

Is there something wrong with my task or launch file?