Signal strength just awful

Recently purchased a ring door bell 4. However, I've found that the WiFi strength is always awful. I was living in my original house with virgin Internet, it was about 4 meters from the ring door bell. Got rssi 70. I couldn't move the router so I put in a WiFi booster in the socket the other side of the door. It got 65. Barely an improvement. I since moved to a new house. Got Vodafone Internet. The router is 3m from the ring door bell. I get rssi 85. I then installed my own WiFi 6 unifi mesh system, I put one point right the opposite side of the door to the ring door bell... Got rssi 65. I just don't get what's going on. I even opened the door and put the WiFi point next to it and still got rssi 65. This ring doorbell 4 cost £179, these new mesh system points are 170 each also. So I've spent out trying to get this sorted but cannot get the signal strength up. Nothing else has issues with signal in the house at all. Anyone else got this issue?