Apple watch series 5 battery indicator stuck at 100%

Hi. I have had the series 5 watch for around 5-6 weeks now. It has all been gong fine until about a week ago when i noticed that the battery appeared to be holding a better charge day by day. I was charging it every day beforehand as it was down to around the 45% mark at nights. Then i noticed it wasn't dropping below 74% then around 86% then ultimately it is showing 100% permanently. At first I did try leaving it to see how long it would last before the battery died and it came down to around 74% after a day and a half and then went flat.

I've checked the software, which is up to date, and tried restarting/hard restarting it and that did appear to work for a couple of days and then it was right back to a permanent 100%. I've tried looking online to see if i could ask someone at Apple the question but all you find in the apple support is the option to send it back for repair and not to talk to anyone?

Anyone else having the same issues with the battery being stuck on 100%?