I used to the app too. I don't have to reboot the router to get it appeared on the app. It's better to contact tplink support directly to figure it out and you could pass your feedback about changing...

Hi, Send email to tplink or call them. https://www.tp-link.com/en/support-contact.html#Hotline-Support

All right. May contact tplink support to confirm it.

There is no such settings to make it automatically but generally speaking it will connect automatically unless something has been. Maybe after the power outage, your router rebooted and some wireless...

Reduce number of clients. Update firmware. Contact tplink support.

There are 4 bands for 5G. Only band 1,2,3 are allowed in the UK. And for band 2 and band 3 (higher channel), it requires the router to pass the DFS certificate which is not compulsory. C7 cannot...