WowAce

-> What steps will reproduce the problem?
The problem happens very rarely after leaving a party or raid. I play for a few hours daily and have it perhaps 2-3 times a month, which makes it difficult to reproduce. I'm not sure if it occurs only when leaving the party through the dungeon finder tool (which leaves the party AND puts you into a loading screen simultaneously).

-> What is the expected output? What do you see instead?
After leaving a party or raid, I would expect to see myself in the Grid2 layout, since I have set "Solo w/ pet" as my Solo layout. Instead, when this bug occurs, the Grid2 layout frame becomes empty, i.e. only a few pixels in width/height and it does not contain any unit frames.

-> What Grid2 version and language of WoW are you using?
r786, German

-> Do you have an error log of what happened?
There's no Lua error.

->Please provide any additional information below.
I will attach some screen shots.
Upon inspection of the Grid2Layout global variable, some values seem to be incorrectly set when the bug occurs.
Usually, Grid2Layout.groupsUsed[<group number>][<member number>].unit holds the unitname of shown units. However, when the bug occurs, none of the .unit keys exist. I'm not sure if this is helpful.
I suspect that when leaving the party, Grid2 clears its layout but somehow forgets to activate the solo layout.