Firmware 4.22.15190 has been released for all devices except the Mini. There aren't many visible changes. The changes that I know of are:
- Search filter in store can filter on languages.
- Busybox has been upgraded to 1.31.1.
- dosfstools has been updated. This should reduce the frequency that Windows reports the device file system is dirty.
- The bug where the menu bar in kepubs displayed the wrong icon is fixed.
- In the store, the filter in the different featured list no longer has the misleading "Featured" entry.
For calibre, there are no changes except to bump the supported firmware version.This will be in the next calibre release. Until then, it is safe to use the "Attempt to support newer firmware" option in the drivers.