I've created a validation rule which checks for a managed custom permission. This validation rule was created within the UI and allowed me to use the "Insert Field" button to insert the custom permission field, so obivously it must exist and be available within the org.

When the validation rule is run, it errors with "10:51:13:002 VALIDATION_FORMULA ERROR:Field Network_Admin does not exist. Check spelling."

The validation rule is simply "$Permission.synapticsf__Network_Admin"

I find it a bit strange that the error message doesn't include the namespace of the custom permission but that might not be relavant. In any case the validation rule when executed can't seem to locate the custom permission and I wanted to know if I'm missing something, doing something wrong or whether this an issue within Salesforce. Any help appreicated 

I'm trying to extend the current LWC Datatable to support dependent picklist during inline editing. 
In LWC Datatable during in line edit, I want to be able to refresh the values of the controlled field when a controlling field value changes. Is there a way to just refresh the cell where the controlled field resides? Reloading the entire table when the controlled field changes is not ideal since that will have huge impact on performance and will bring other problems.
Ideally I would like to reload just the cell but if that is not possible, is it possible to reload maybe an entire column or row without reloading the entire table?