@Chris972 

I have exactly the same issue.
I tried with Manual Band, setting the ones are most close to my house (1, 3, 7, etc...) but still getting several time disconnected/connected.

Now I found a thread where someone have solved setting like this:

It came from this thread - https://community.tp-link.com/en/home/forum/topic/176312?page=12 - "Enabling IGMP Snooping in the Advanced tab under Network/LAN Settings seems to have solved the issue". I have done this and it does seem to have stopped the constant dropping of connection.

I've just set the IGMP Snooping... let's see if it works....

  @SimoneG76 I'll try, even if it's very difficult to judge since the problem hasn't recurred for me since.
Thanks!

  @Chris972 

and what did you do to do not getting the disconnection ?

Because I've just verified that, even with this setting, I got again a 4 minutes outage of the connection 

  @SimoneG76 
I didn't actually do anything, except select two bands, but I'd already done that before.
This proves that this problem is quite erratic and that the firmware isn't up to scratch (not to mention the problem of lowering the MTU when connecting to a VPN server).