Illustrator v30.2.1 hangs when offline and switching documents

When not connected to the internet, Illustrator hangs when switching documents (Mac spinning wheel). Other operations also seem sluggish at times.

This occurs on a fresh Mac install (Mac OS Tahoe 26.3). It appears to have been introduced in either Illustrator v30.2 (not tested) or v30.2.1 (tested). I’ve gone back to v30.1, which does not have the problem.

The following issue seems to report the opposite problem (maybe a fix has created this new issue):