Force 5GHz Wifi connection because I use a mesh network

I purchased a TP-Link Deco M9 Plus mesh Wifi network and it broadcasts the same SSID for both 2.4 and 5 GHz and you cannot set a unique SSID per frequency. I can only disable either frequncy, but I need both frequencies because I have older 2.4GHz-only devices but newer ones as well. Out of the 19 devices I have at home, only my MacBook Air running macOS 10.15.4 Catalina has consistent problems connecting.

Reading older discussions here and after working with TP-Link support, it seems like the MacBook has problems connecting when the same SSID is broadcast on both 2.4 and 5GHz.

I've searched for settings that are readily accessible (e.g. Network Preferences, System Information) to force this - to no avail.

Does anyone know a way to force the MacBook Air Wifi adapter to use only the 5Ghz frequency?