Module weirdness

We have a custom module (psm1) which has worked for years. Today I was debugging a script and when calling a function in that custom module and pressing F11, it skipped the function call instead of opening the module file and going into the function. I edited the module and saw the function exists. I did an import-module -force and then a get-module and saw the function name listed under ExportedCommands. The weird thing is that if I do a get-module -listavailable, the module is listed but that particular function does not appear in the ExportedCcommands??? I have confirmed that the module does not appear in any other module paths. Why would there be a difference between the functions listed on get-module and get-module -listavailable?
Thanks
David

An updated - I did find the function in the ‘-listavailable’ eventually. So the issue is why did the debugger skip the function call (when pressing F11) when the function clearly exists?

Nothing made sense. I tried to debug it on other computers. I dragged the function out of the module and put it in the script itself. I changed the name of the function. Whatever I did, F11 just refused to run that function. Other module functions in the same script worked fine - F11 would open the module and debugging continued. The only solution was to grab the code from the function itself and stick it in the script. Its just too weird.