Hello,
Normally this shouldn't be a problem, but it's better to separate the 5GHz and 2.4GHz SSIDs so that the doorbell doesn't try to connect to the 5GHz network.
This behaviour is often poorly managed by access points, which always try to connect at the highest speed.
Another point is to check the bandwidth (20 Mhz or 40 Mhz) which can also cause connection problems.
Good luck and best regards

Perhaps the "Tether" app from TP-Link can help. If the device is WPS-capable, you have to press the button on the back of the router.