I have Xiaomi AX3600 with newest Openwrt installed about 2 weeks ago. I usually ssh from my phone connected with wifi to my desktop pc, connected over wifi too.
I have setup both AX3600 radios using same SSID and 802.11r. Additionally on the 2.4 GHZ radio I have addional SSID to be able to manually connect to 2.4 GHZ when i am further from wifi as it works better than default SSID with 802.11r.
However i have noticed that when i restart the router everything works ok. But after about half day - day, I cannot connect over ssh to my desktop pc from my phone (5GHZ wirelesss -> 5GHZ wireless). But I can ssh to the router just ok (5GHZ wirelesss -> wired). I have also noticed that when I switch my phone to 2.4 GHZ SSID, I can ssh to the desktop pc again (2.4GHZ wirelesss -> 5GHZ wireless).
This is an issue also because i have multiple Amazon Echoes and they cannot see each other and i cannot use multiroom audio too.
I have also encountered the same problem. Have you found a solution?
I am currently using frps+frpc for local forwarding temporarily, but it is too troublesome.