Poor RSSI score

Hi there I have been having problems with missed events blurry images and completely black images the motion detection is at the maximum level but still missing events! RSSI is never below -60 so suggests my signal is bad. I have the fastest internet with VM 1 Gig. I have tried calling Ring and have been charged £27.36 for a 7 minute call! I’m not happy about this please sort this out! We have an open plan house and router is about 6 metres from the front door with only the wall in its path. I have paid over £150 for this doorbell and it does not seem fit for purpose! Looking forward to hearing from you. Leanne