Montellese, I want to thank you for keeping me from throwing a perfectly good Raspberry Pi 3 B+ out the window of a moving car. I was starting to really consider it with this issue. I went through the trouble of creating an account here specifically to thank you. I also want to let you know that my symptoms were even worse then a menu that kept disappearing. I had that symptom combined with the inability to connect to wireless networks. I would try to connect to them and receive an error popup about "invalid arguments" with no passkey prompt. eventually, the UI would freeze completely and I had to pull the plug. After removing the bluetooth audio device changer service add-on, I have access to the UI again. I don't remember installing this add-on so I presume it is pre-installed. Again, thank you so much! I only use it for my daughter in the car, but she is 2 years old so it was nice not having to hear Trolls, Moana or Elsa for a few days at least. 
Adam