Hello, I am reporting a reproducible issue with the Linux rtw88 driver affecting a Realtek RTL8821AU USB Wi-Fi a dapter during monitor-mode channel hopping. Hardware: TP-Lin k Archer T2U Plus USB ID: 2357:0120 Chipset: Realtek RTL8821 AU Software: Ubuntu Linux Kernel: 7.0.0-28-generic Kismet Ob served problem: When Kismet performs normal channel hopping, the kernel reports warnings involving: drivers/net/wireless /realtek/rtw88/phy.c Function: rtw_get_channel_group() Testi ng showed: Kismet locked to Channel 36 runs without triggeri ng the warnings. Enabling channel hopping causes the warning s to return. The issue appears when the adapter reaches uppe r 5 GHz UNII-3 channels (149–165), especially Channel 157. This appears to be a driver issue involving 5 GHz channel g rouping logic in rtw88. The behavior is reproducible and app ears to be triggered by normal monitor-mode channel hopping. I am not a kernel developer and I am not submitting a patch . I am reporting the issu.