Hello Barel,
I think this is normal. It does not print if the maximum session open if the printer is LOCL. I have encountered the same issue. You have check if maximum sessions are opened, before going for print.
Also, I have encountered a similar issue while debugging where if maximum session are open, then even if we have put breakpoints in program, it will not go in debug mode, but will get executed directly/ it skips or suppresses the debug screen.
Hence these are some constraints from SAP GUi end.
Thanks,
M M Jaffer.