Bug: Private chat tabs closed/discarded without manually doing so

[redactedscribe]

Nicotine+ version: Nicotine+ 3.0.0.dev1
Operating System/Distribution: Windows 10 20H2

Describe the bug

For currently unknown reasons, all my private chat tabs were closed.

Expected behavior

Private chats should remain open as tabs for as long as they are not closed.

Additional context

Could this be related to the new auto-connect on start-up feature? A quick test said no. I don't believe I've noticed this happening before.

[mathiascode]

Seems to happen if you open Nicotine+ and close it without connecting.