When my toolbar is loaded (by menuload or netload), the F2 doesn't work anymore, it does open but it goes hiding at the back of Autocad. I know that I don't give a lot of information but I just don't know what other information you could need .. so feel free to ask
Are you loading your toolbar from a partial customization file?
I just created a partial .cuix and F2 (AutoCAD Text Windows) show up just fine.
Try with a backup of your acad.cuix, if you don't have it, try to find it in the AutoCAD installation folder under UserCache