I've got a SQL Server 2016 AG set up with only two replicas (primary and secondary). Both synchronous, non-readable secondary, and backup the primary only.
Transaction Log backups occur on the primary replica via scheduled SQL Jobs that execute on both replicas every half hour. Full backups occur nightly. FULL recovery model.
The issue is over time the secondary replica log file eventually grows to be larger than the data file, while the primary remains fine. The only thing I do that helps is a manual failover, which seems to kick off the log backup jobs on the (now old) secondary replica since its readable again. Any tips on how to handle this?