Night Vision stops working

Hello community, I have a problem with my floodlights cam... I have 3 around the house and I use them for I don't know 4 years? I first realized that there is really a problem only few days ago. First cam that had a night vision issue was my front door cam and the problem is similar to what [Cris-ness](https://community.ring.com/u/Cris-ness) described in his post and as it is mentioned in the solution I initially thought it is a change in the street lighting that prevents the night vision to work. But this weekend I saw that my second camera also shows black screen during the night - no change in the environment and it was working before I'm sure this can be checked and compared with past recordings.. any ideas?