After latest software, HRV and sleep tracking have gaps

I have the 265s for two weeks now, and since yesterday the HRV tracking seems off with many gaps.

Same with sleep tracking, I slept full 8 hours and it only counted 3 hours which impacts every metric on the watch, unfortunately enough.

I haven't changed anything on my habits or sleeping patterns, watch is snug on my wrist as always.

Could it be a software related issue or should I go and let the HR sensor be checked?