MASM32 Downloads
I haven't been able to reproduce this and I have left my copy running since 22/07/2019. I've tried to cause it to crash or cause other odd issues, but still nothing like what your describing. I'm not sure what I can suggest to fix this issue.
I looked at the x64 version and seen that it had the issue you described. I updated the traymenu control that had a couple missing lines from porting over from the x86 version, and it appears to have fixed the disappearing icon when you mouse over it. I updated the first post with the updated x64 version of TrayInfo.