Reolink battery drain while on hardwire?

I have just had my reolink doorbell for a few days and it gives me loads of headaches already.
I have the version which can be both hardwired and run on battery. I installed it on saturday (temps around 4-5 deg) and it charged from 90 to a 100%. Got the reolink HUB on sunday and integrated in HA and now at night it the battery just slowly drains (status constantly changes from awake to sleep). It was at 78% this morning, stayed at that level for just about the whole day and now dark (and bit colder) is draining again, about 5% in 3hours.
Can’t figure why it’s draining and why does a hardwire device even look at battery status?

Any help woul dbe appreciated.