Ring Doorbell 3 plus, hardwired, on a 8v feed, not charging

i set up my new ring doorbell 3 plus, 3 weeks ago and initially it showed hardwired, but no charge to the battery was noticed. eventually i called support, who checked everything..... i was wired correctly, it was showing hardwired and i was told to reduce the sensitivity etc to help my doorbell trickle charge the battery. so i did what i was told, reduced its activity, motion sensitivity etc to the very minimum, just to see what happened. The doorbell seemed to be ok, the battery seemed to sit around the 75% level, up a little, down a little, so i accepted maybe the 8v feed was a bit low. 5 days ago, my doorbell showed it was on a solar feed (i dont have a solar surround), so i thought maybe the voltage is so low, my ring thinks its a solar feed. today, my device has changed from hardwired to battery and my battery is depleting. I just dont know what more i can do? any ideas?