Hi @AlexCristian ,
Do you mean that you could retrieve records from your NAV table, but you could not update them within your app?
Which permission do you have for the NAV table? Only Read-Only permission?
Based on the issue that you mentioned, it seems to tell that you have read permission to the NAV table but not edit permission to your NAV table.
On your side, please check if your current account have proper Edit permission to your NAV Table.
Note: PowerApps app inherits data access permission from data source itself.
In addition, the Dynamics NAV conector is a Premium connector, please make sure that your current account have owned PowerApps Plan 1 license at least.
Also please consider take a try to re-create a new connection to your NAV Table from your app, then try your Patch function again, check if the issue is solved.
Best regards,