Same with Raspberry Pi 4, which now seems to only be able to use one network interface.
I have a Ralink Technology, Corp. MT7601U Wireless Adapter, which I have been using as the second wireless NIC along with the on-board wifi. After upgrade, only the Ralink seen and working, and if a LAN cable plugged in and eth0 used, the ralink is not available despite present as seen with lsusb.
I'm getting weirdness with the update as well, which manifests itself as such: A RPi3B+ Plugged into HDMI at power-on: works fine, but HDMI unplugged and I get a couple of flashes on the green LED and that's it: otherwise brick-like.
Another one seeing weirdness with updates. I have headless RPi4 and RPi3 configure identically and running linux-rpi on the same wifi network. After recent updates, the RPi4 will not connect to the wifi, constantly outputting wlan0 CTRL-EVENT-ASSOC-REJECT errors. After a heap of trial and error, I found that deleting the dtoverlay=vc4-kms-v3d line in /boot/config.txt fixes the problem.
Actually, my issue looks to be a bug in wpa_supplicant which was upgraded 2:2.9-8 -> 2:2.10-1 a few days ago. I get the same CTRL-EVENT-ASSOC-REJECT errors as this.