I have observed this twice, so now I’m sure that this is the case.
To reproduce:
Close Antigravity (Agentic) for an update (same with clicking the restart button).
Wait for a few seconds.
Observe that all Antigravity IDE instances are closed.
And again, these open chats in Antigravity IDE are lost on UI after restart!
I’m really tired of these bugs.
Note: Losing chats from UI happens in different ways too; not just this way.
Antigravity (Agentic): one version earlier than 2.15.0
Antigravity IDE: 2.5.5