Why is my Apple Watch Afib history not reporting?

Afib History was enabled last fall (2024) and reported weekly updates without any issues until this week when it failed to report any updated info.

The Watch model is a 10 and the OS is the latest version (11.5).

Afib History is enabled.

All other Heart-related monitoring like ECG, HRV, etc seem to be working as expected.

Watch has been worn 23/24 hours each day over the past week.

Any ideas? Thanks.

[Re-Titled by Moderator]