Configuration keeps reverting to namespace topp

(This concerns the landgate datastore and associated feature types on instance vector-unstable on Atlas)

I've added the datastore landgate and created a new namespace landgate for it. After restarting all the layers can be found as <namespace>:layername

But if you add or change a featuretype (changing cache time appears to be enough), the namespace for all featuretypes associated with this datastore reverts to "topp"

Restarting GeoServer fixes the issue.