Backup folder not being created by HA

I’ve set up some network storage for my HA Promox install to use but the named folder isn’t being created after completing the ‘update network storage’ setup page (in this case the folder should be called HABackup as in the picture). The .tar files are created on the relevant NAS drive but they just sit and accumulate in the root folder rather than the requested folder being created and dropping in there. I’m sure it used to work on a previous install but not now. Any ideas?