Hello @Hobba 

If the 2.4G network or connection is not stable, there might be strong wireless interference around you on the 2.4GHz band, you can check that with a Wi-Fi analyzer.

If that's the case, try selecting the least crowded wireless channel and setting it in the AX55 wireless settings instead of using Auto for Channel to improve your wireless experience.

You can also try to change the wireless security to WPA2-PSK AES, channel width to 20MHz, and mode to 802.11 b/g/n mixed.

BTW, what are the 2.4G client devices? Do all of them only support 2.4G connection?

@Hobba 

Thank you very much for getting back with the detailed info.

To assist and figure it out efficiently, I've forwarded your case to the TP-Link support engineers who will contact you with your registered email address later. Please pay attention to your email box for follow-up.