@Bingoig11 I also found this, you can try to use the latest firmware which released by TP-Link. Not sure which country are you based in, if you cannot find this firmware version on official TP-Link...

@Bingoig11 Hi, you may try to disable Fast Roaming and advanced features on Deco APP temporarily for a test, sometimes clients fail to connect to the Deco Wi-Fi when Fast Roaming enabled. If you can...