I would start from finding the reason for “Action can’t be completed” message. It can appear in various cases, but most of these cases are related to some issue with database backend. If an error occurs, no subsequent actions are executed.
You can see the error itself in a browser console:
go to the screen from which you run the action
click on the button which is not working
see what error occurs.
If it’s a database error, you will see it in the log.
Then you can try to understand what caused this error, but this will depend on the error itself. You can compare the URL in the call with your DB collection ids (found in API section), to see with what table do you have the issue.
Sorry, but debug of such things might be complicated.
Given that you’re creating record in Adalo collection and updating record in Adalo collection, and take values from the External collection, my guess will be that some value from an External collection contains data which is not accepted by Adalo backend. But this is a guess