Assuming you have a device_tracker group, the device tracker entity platform requires an update (Changes in setup entity platforms with group integration | Home Assistant Developer Docs). This link is on the backwards incompatible list for developers on the release page, however seems like not all entity platforms have been updated yet. Will likely get fixed soon. Probably an issue ticket already exists on GitHub (edit, yes it does: "Old style" groups: Lock groups show states "off/on" instead of "locked/unlocked" · Issue #119032 · home-assistant/core · GitHub)
Shitty thing is that I just updated all to on/off and probably have to change it back later when it gets fixed.
