Very detailed problem description
Multi monitor is not the issue since I run mostly that way as well.
Either laptop with fixed monitor using hdmi, either laptop using usb-c asus zenscreen.
No problem. So it can't be multi monitor on itself.
Thanks for your reply, comments.
Do you have winbox session open for more than a few hours? (and i assume your on windows10, correct?)
(also i have a feeling that its related to several monitors, or it gets worse/more frequent when you have 3x or more monitors- this is just a guess from my experience).
In my experience this most frequently seems to happen with 3x or more monitors in total (including a laptops screen as 1 of the 3x, so 2x external monitors when ive seen it repeaadly occur on my laptop)
I thought i was close to getting this as a repeatable issue this morning, as i was able to make it occur 2x times in a row, both times *NEWLY* opened winbox sessions (to my local network, office mikrotik) i was able to get winbox to crash / disappear both times when clicking the "IP ->" menu (when winbox was in the background).
(winbox was on my upper monitor, so not on the main monitor, and i had 4x other winbox "sub-windows" open: Interface , Dhcp-server->Lease, Log, Firewall). I then clicked over to chrome, and clicked directly on the IP menu of winbox and it disappeared). the 2nd time it took a few tries (clicking desktop or chrome, then winbox->IP menu). After this 2nd time, i was not able to repeat it again. (but i know it will happen more, later today).
I do feel its occurs more frequently when clicking the IP menu in winbox.
To update, i have deleted as much as i can in my: %appdata%\mikrotik\winbox\ folder however i did not want to delete several .session files as those contain my custom winbox layouts for some routers i frequently use. ( also i dont see any connection to X router and Y .session file, as ive seen this occur on fresh, brand new mikrotiks we have deployed. (ie as its my first winbox session on those devices, a .session file has not even been saved/created yet, and the disappear issue will still occur).
Mikrotik support has requested that i send them a video of it occurring, this will be a bit difficult as its random, but i will try. (i sent them a video of the process though).
any feedback is appreciated, thanks