I have a field where I’ve placed a URL type Button to open the record in an Interface I’ve built.
The interface has a dropdown with the record name field available and when I pick a record from that dropdown, the Interface loads the correct data and displays it correctly.
When I launch the Interface from the record Button in the table, the record ID passed to the Interface does not seem to correspond to any real record and so the Interface is blank. I can then use the dropdown to pick the record I planned to have open automatically and I see that the record ID in the URL is not the same as what came from the table Button.
The url format for opening a record in an interface is different from opening in the regular UI. It is a query parameter that sets the value of the record picker.
The format of the button formula looks right to me. Are you sure you have the right id for the record picker in that page? (In your post you are using the record picker id GUu5w but you also state that you’ve changed some of the letters.)