heart rate sensor doesn't work anymore (WHR version 0.00)

I have a problem with my forerunner 955 with firmware 18.15. It constantly trying to update. Since it updated the heart rate sensor doesn't work anymore. In "Info" it says "BMX: 0.0.0. (!)", "WHR 0.00.00" and "Sensor Hub: 0.01". The watch also doesn’t connect to WiFi anymore, due to „low battery“, but the battery is almost 100%. It have already connected it to Garmin Express and also deleted the "RemoteSW" folder. But no effect. I guess it is some kind of update error. Does someone know how to fix it?