SSRS subscriptions stuck at Pending

Hi all. I am new to SSRS and hope this is the right place to pose this question. We have 19 subscriptions that are all stuck at the Pending status.
They all email reports except one that places a file on a share.
The subscriptions all run successfully and deliver their reports, but the status stays at pending.
We are running SQL 2016. The reports are all data driven, they all deliver Excel-rendered reports.
I have verified that the owner has been changed to a service account. The email addresses they deliver reports to are valid addresses. The logs show no errors.
I have googled this topic to death and found nothing helpful. If anyone has any ideas I would be very grateful.