Sparsebundle mounts as readonly

As I can’t mount the personal space from my cloud as a normal disk (i.e. access it via the command line etc except through a silly file patch via Library/containers) I created a sparcebundle which I can then mount as a normal disk. This worked fine originally as I was able to write to it, but at some point it became mounted as read-only and i can no longer write to it.

any one have any idea what is going on and why is is now mounted as read-only and more importantly how to mount it as read-write?