SAAS - Mass delete Change Log Entry not working

Hi, We have a customer who is running on SAAS. When we create a sandbox we have a process that truncates change log entries to get the database size down. we have a codeunit that has explicit permission of RIMD for table 405 and the user also has permission for RMID table 405. This has been working for a few months but when i tried to run it yesterday i get an error saying that "your license doesn't grant you the following permission on Tabledata 405 Change Log Entry: delete

image.png

I am at a loss as to why its suddenly stopped working - does anyone have any ideas please??

many thanks