Process model stuck in "Active" state but not progressing

Hi Everyone,

I'm running into an issue where one of my Appian process models stays in the "Active" state but doesn’t actually move forward past the first node. There are no errors in the logs, and all inputs look correct. It's just... stuck.

I tried canceling and redeploying, even restarting the Appian engine, but the same thing happens again. This process used to work fine a week ago  nothing significant has changed in the model.

Could this be related to a timer event or a data store node silently failing?

Thanks!