I have been having this troubleshooting for a while now. Everytime I go to presentation mode and then exit this mode (back to normal). All my toolbars disappears (see attachment). It's really annoying. The only way to bring them back is to reset my workspace or drag InDesign to my main laptop screen (on laptop they are immediately visible again) and then drag it back to my external monitor. It's bothering me quite a lot. I like to toggle between normal and presentation mode constantly. And it's been slowing me down, and giving me stress.
Have you guys been having this too? My gut is telling me it's hardware related, but I am not sure.