1. We have some Custom Actions, inherited from PostBackAction.
2. These actions are implemented to use SelectionGroups.
3. When we select the Record, IsSupported of the Action is called, and it is correct.
4. When we change the Selection (selecting another Record) the IsSupported is not being called. It looks, it is cached.
Adam Support answered - "IsSupported" is called only on the first selection and this is done for performance reasons.
Customer support service by UserEcho