Cagefs issue !!
Can you check with cpanel the following
If we transfer the accounts from one disk to another suppose we need to transfer one account from /home to /home2 by using account functions->rearrange accounts of WHM it will fails if the cagefs is active and also it will partially copies data to /home2 and the domain will go for offline otherwise we need to rsync the same account back from /home2 to /home for make the site online. If we disable cage then possible to transfer and after we need to re enable the same.
Richard Hordern commented
The hook was implemented in cPanel 54. I haven't tried to rearrange an account recently. Has this been fixed ?
AdminIgor Seletskiy (CEO, Cloud Linux) commented
We are working on the issue with cPanel. At this moment -- it is impossible to implement, as it requires some kind of hook for us to know when account is 're-arranged'.
More info here:
Please, make sure you vote for this feature on cPanel site as well.