After d-u (and 2 subsequent ones) wifi just stopped working with 5.7 kernels (5.7.4, 5.7.6, 5.7.7) but still works fine when booting an older kernel 5.6.17. Device is (with 5.6 kernel):
Device-1: Qualcomm Atheros TP-Link TL-WN821N v3 / TL-WN822N v2 802.11n [Atheros
AR7010+AR9287]
type: USB driver: ath9k_htc
IF: wlxf8d1111403eb state: up
With 5.7 kernel device is recognised in lsusb and lsmod shows driver is loaded but journalctl shows (98 attempts):
$ journalctl -b -p3
Jul 02 09:29:24 siduction-brain2 kernel: ath: phy98: Reading Magic # failed
Jul 02 09:29:24 siduction-brain2 kernel: ath: phy98: Unable to initialize hardware; initialization status: -5
Jul 02 09:29:24 siduction-brain2 kernel: ath: phy98: Unable to initialize hardware; initialization status: -5
Jul 02 09:29:24 siduction-brain2 kernel: ath9k_htc: Failed to initialize the device