I encountered all those glitches while putting one of my monitors in portrait (vertical) position, none of this was seen before with 3 landscape monitors The problems are: (see the video for better understanding) - The application launcher ("start menu") is not positioned correctly - It's impossible to drag windows correctly, they hang at some point and resize/teleport randomly, making the desktop unusable - Yakuake doesn't work - I noticed also issues with the background in the vertical monitor (background being in landscape mode leaving a black space) but i couldn't reproduce after updating to 5.6.1 so *maybe* it's fixed - I noticed also issues with the cursor size, it was changing its size randomly, i later forced it to the small size, the change took effect after restarting Another guy on irc had similar problems with a portrait monitor Video: https://www.youtube.com/watch?v=WpbPixYt19k I found a temporary fix, just changing an option on the screen settings and applying. But yakuake still doesn't work after. And it breaks again after logout/restart. Video of the fix: https://www.youtube.com/watch?v=auSDQTyYMQo The problem is always reproducible here
I opened other bug reports for all the individual problems listed here, this can be closed.