Veeam > Synthenic full transform backup not clearing previous fulls

I've got a job that's dropping .5TB on my NAS each week, but it doesn't clear the previous ones.  I've tried a synthetic full as well as active full.  What could be the cause?

Veeam 7.0.0.771, patched.

Logs are ready if needed.

Thanks in advance for all efforts atbgood guidance.