Unable to modify ServiceDesk instances in ESM admin settings

We have recently acquired a license for out ServiceDesk Plus, after using a trial one that allowed us to test the ESM features.

We have found it useful to have at least two portals, so we went ahead and purchased a license.

Unfortunately, we are facing some issues when trying to modify the current ServiceDesk instances:

We are unable to delete instances anymore, the owner cannot be changed and the licenses can't be reassigned to other instances. The general behavior of the application is like it is preventing any changes from being saved (only happening in the ESM admin menu). We have tried making the changes from Firefox, Chrome, Internet Explorer, but the same thing happens (nothing is saved).

We have also updated to the latest SDP version available (as of today, v11.1 Build 11122), but that didn't make any difference.

Please help!