I purchased my S21 about 5 weeks ago and I am not sure if I have been experiencing this issue since I bought it but in the last week, I have noticed this issue. When my phone is locked, the AOD will either show for a few seconds to a minute or just won't show. I've ensured it is set to always show, power-saving not set to turn it off, no Bixby routines and any updates are installed for phone/AOD. I've even factory reset my phone and removed the case and screen protector and the issues are still persisting. Does anyone else experience this issue?