Connected new kit up - good connection and signal everywhere including in garden building where I want the extended wifi. As soon as I use the internet in the garden building - play a video on tik tok for instance - the internet cuts out in whole house. Has done this 3 times now so it must be as a result of the new extender. Have to turn off router each time for twenty minutes to regain internet. Connection/signal remains full throughout. Any ideas or help would be very appreciated.