Here are some pointers to note when troubleshooting issues with Business Rules,
Prerequisite for Requester specific rules: Rules set up for the requester portal will work only if the fields are visible and editable to the requester. So ensure that the 2 checkboxes highlighted below are checked.
Order of the Rules to Resolve Conflicts: If you’ve got multiple rules set up to act on the same fields, the order of the rules determine the final state of the field i.e the rule that executes last for a particular field.
Enforcing Rules System-Wide: Certain rules can be enforced across all channels, such as List view edits, APIs, Bulk Action, etc. For example: If you’ve disabled a field and want to ensure that the field cannot be edited via these other channels, you simply need to check the Enforce System-wide checkbox.
Note: Showing and Hiding actions are not supported with the enforce system-wide option which means that these actions are limited to the forms.