Set priority of Fast Transition to 2.4 GHz on Keenetic router

I have Keenetic Hopper (KN-3810) router and S24 smartphone. How can I set priority of 'Fast Transition' and 'Radio Resource BSS Transition Management (802.11k/v)' to 2.4 GHz? When using the smartphone, if I move into a room with a poor 5 GHz signal (2 bars, around 20%), the phone does not switch to 2.4 GHz. I enabled debug on WifiMaster0 and WifiMaster1, and judging by the logs, the router does not send a BTM (BSS Transition Management) request to my phone to trigger a switch to 2.4 GHz. Is it possible to prioritize 2.4 GHz for Fast Transition?

Question by datafile4 on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.