|Check three things:|
The person is in a group and the group entry in the ACL is not set to "Person Group" type, and set to "Person".
There was a glitch as some Domino version that if the person was setup this way, the person will be able to edit documents and save, but not updated fields or delete documents via hotspots.
The ACL for the Database has Internet Access level set to Editor.
That consistent ACL across replicas is set if you are changing the ACL on a different server replica than the person with the problem is using.