I for one have an RPi4 running the same kernel (4.19.93) and a Logitech wireless mouse/keyboard which didn't stop working after the update. Here's my output of lsusb listing a "Logitech, Inc. Unifying Receiver":
Bus 002 Device 003: ID 2109:0711 VIA Labs, Inc.
Bus 002 Device 002: ID 0480:0900 Toshiba America Inc
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 046d:c534 Logitech, Inc. Unifying Receiver
Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
If you wish to investigate the problem, you should make your test repeatable (and your question much shorter):
- install a vanilla Buster image before the update, verify that the keyboard works
- install a vanilla Buster image after the update, verify that the keyboard stops working
- open SSH access or a serial console on the RPi and compare the output of diagnostic commands (
dmesg | grep usb,lsmodandlsusbwould be a start) between the two systems. Post those differences.