Doorbell 3 does not always register motion

Had many wi-fi problems with my new Doorbell 3+ which I thought I'd cured after installing a wi-fi booster, the RSSI is now registering 50. The problem I now have is that the camera never seems to want to log onto live view, it times out after about 10 seconds & always takes at least 2 attempts to log on. The second problem I'm having is that camera doesn't always detect live motion & record, probably missing at least 50%, this includes postman visits & cars comming up the drive. It's missed 2 events this afternoon, one was an "on foot" delivery of a bundle of newspapers & the second was me leaving the house in the car, although it did pick up my return. At the rear of the house, I have also installed 2 Stick Up cameras which seem to work fine, they always log to live immediently & always react to & record motion, even though the RSSI is higher at around 65, & that's using an existing wi-fi booster I have in a conservatory! I didn't expect to have to spend £20 on a wi-fi range booster & have so much hassle/unreliablity with the door bell for what is a moderately expensive product! What's wrong with the dor bell, is it faulty?