FRITZ!Box on Twitter: "@jiribrejcha You do have the option to disable 2.4 GHz. Go to Wireless > Radionetwork and uncheck the box 2.4 GHz. You can also adjust radio channel settings at
AVM Wi-Fi 6 in the test: Fritz! Box 7590 AX and Fritz! Repeater 6000 with 2.5 GbE | AllInfo
AVM FRITZ! WLAN Mesh Repeater 3000 (three radio units: 5 GHz (up to 1,733 MBit / s),