Hi,

Could you please check with the below script in your UI action:

(function () {
	if(gs.getUser().isMemberOf(current.assignment_group)){
		current.state = 2;
		current.u_on_hold_reason = '';
		current.assignment_group = current.u_previous_assignment_group;
		current.assigned_to = '';
		current.update();
	}
})();

Also, please provide the code you used in UI action, it will be more clear to understand where is the issue exactly.

Please mark this correct/helpful, if it resolves your issue.

Thanks