make [1]: *** read jobs pipe: Resource temporarily unavailable. Stop

I am facing this problem for a while:

make [1]: *** read jobs pipe: Resource temporarily unavailable. Stop.

I have a top-level makefile that "calls" additional cmake and make based on the rules.

target A is a relatively small code (C/C++). target B is much bigger.

The issue happens mainly during the building target B but not always. I use make 3.82.

I have tried with make 4.3 and it occurs always.

Here is a skeleton of my build system:

MAKEFLAGS = --jobs=10 --max-load=20

<target A>:
    +. /usr/share/Modules/init/bash &&
    module load <target> &&
    cmake --build <project buildsystem> --target <target A>

<target B>: <target A>
    +. /usr/share/Modules/init/bash &&
    module load <target> &&
    make -C <path> <target B> &&
    cmake --build <project buildsystem> --target <target B>

/usr/share/Modules/init/bash

The Modules package and the module command are initialized when a shell-specific initialization script is sourced into the shell. The script creates the module command as either an alias or function and creates Modules environment variables.

https://modules.readthedocs.io/en/latest/module.html

(--max-load is equal the number of cores on the build sever. --jobs is half of it.)

I have verified the MAKEFLAGS passes correctly (I have checked the number of gcc/g++ processes during build) and I don't have this warning:

warning: -jN forced in submake: disabling jobserver mode.

Host OS: RedHat 7.6

cmake: 3.16.4

How can I solve this issue?