Mailbox Sensor Poor Signal

I just purchased a Ring Bridge because of the Mailbox Sensor. We have a very long driveway (around 100 feet). The metal mailbox is attached to a stand across the street and a house or so down along with two other mailboxes. At first, I had a "fair" signal. Then it kept dropping and has had a "poor" signal at best. I found a different window in the house that made it a bit closer (263 feet as the bird flies v. 273 at the first spot). It is not direct line of sight, and there is no option for doing that. Now the sensor is completely disconnected. In the past, power cycling the Bridge has reconnected it, but it's not working. Any suggestions for improving this? I have a waterproof box in our front yard that we have a router extender for a doorbell. I'm sure it would improve the Mailbox signal. I know the Bridge is supposed to be inside, is that due to water? Any information on operating temperature that may make repositioning the Bridge outside a bad idea?