I noticed that this bug is still around, Roblox will reset my plugin layout to having random plugins and windows open when I didn’t do that when I exited Studio last. It seems to be associated with the most recent update to Studio.
Apologies for necro but this was one of the top google search results for this problem so.
Open studio. (No other studio instances open)
Move some panels.
Close studio
Reopen studio - does it save? Are other things present?
Another issue is that in some cases there is a bug during play solo which can pop up plugins randomly. Its important to take note of when exactly this is happening. To work around the play solo issue, try turning on “Load All Built In Plugins in Test Mode” in Studio settings.
@butterthebig
In case it helps with reproducing this bug, I am getting an issue right now where closing studio (via CMD + Q) during a play solo test (on Macbook air M2) causes half of my docked studio docks windows to close completely, and for the layout with those closed to be saved.
This also happens if I disconnect from Team Create sometimes (e.g. by shutting my laptop lid), possibly because I was also in a playtest when I did so.