I have multiple windows open, each one with a bunch of tabs. many of them are with the sleeping icon, as they have been restored after relaunching Orion.
At one time, I felt that the window I was using disappeared. I thought it has been closed, but I can't tell exactly what happened.
I relaunched Orion since this happened, and now I see that 2 windows have the exact same tabs (all sleeping). So it seems that the window that disappeared has been replaced by a copy of one other window (this may have happened when relaunching Orion).
Sorry I can't produce a more precise description of the issue. That was not the first time I had the impression to loose the window I was using, but I thought that I could have close it inadvertently, and I am sure now there is an issue here.
windows should not disappear
0.99.132-beta, 15.3.2
Sequoia (15)