There exist a couple of Global Settings that can cause this issue. They are found in /admin |System Status/Settings | Global Settings.
The Database Backup Set Max Incr Usage value determines the maximum size of the backup that the Primary can send to the Replicas. The Replication Interval determines how often that incremental backup is sent.
To confirm these values are causing the problem, confirm the size of TPAM's incremental backups in /admin | System Status/Settings | Cluster Status | select the Primary and click the "Member Status" tab | in the Backup Set Information section, find the value of Incr Backup Bytes. Divide the value found by 1,000,000 to find how many MBs of disk space each incremental backup requires. If it is larger than 1024 then the cause is confirmed.
Decrease the backup size. Refer to One Identity KB Article ID: 132697 - "What information is included in the backup files? Is it possible to reduce the backup size?"
Increase the global setting Database Backup Set Max Incr Usage to a suggested value of 2048 MB.
Optional: Increase the global setting Replication Interval to a suggested value of 300 seconds.
After these settings have been updated, the clustering service must be restarted. This is done by navigating to /admin | System Status/Settings | Cluster Status | click the "Restart Clustering" button.
Note: Clicking the Restart Clustering button has no impact on active PSM sessions.
After four hours create a new support bundle to see if the error message is cleared.
If the error still appears, the primary will need to be rebooted.