Im going to guess you have an error on the card. the reason Im’ going with this is that in your statement you mentioned it says
SD card memory available says 1.81G/1.86G. the second number after the slash should be the full capacity of the card. have you tried formatting the card since it started saying this?
possible solution. try a format in the camera. if those numbers don’t change, try a full format in a PC.
if that fails I would start a ticket for replacement or refund with Wyze.
Wyze stand behind their products but if you are interested in trying a different card, go with high endurance cards. I havent been able to find an endurance card having an issue in these cameras yet and its what many of us use. this post is a good starting point on whats been working well for people.