== Test plan ==
1. Enable the AllowOfflineCirculation system preference.
2. Go to Circulation -> Built-in offline circulation interface.
3. go to Check out
4. Input anything as a patron barcode and validate
5. you don't get the warning that there isn't a patron DB in offline mode
6. Input anything as an item barcode and validate
7. Nothing happens, no warning about missing date, no recorded checkout when the date is filled
8. Go to offline checkins
9. Input anything as an item barcode and validate
10. Nothing happens
Bisecting shows that it's from bug 29155
Offline circulation uses a plugin, jquery.indexeddb.js, which hasn't been updated for almost ten years. There is an outstanding issue about it being incompatible with jQuery 3.6: https://github.com/axemclion/jquery-indexeddb/issues/75
Ouch, thanks for tracking that down.
Does it look hard to replace?