For some reason I couldn’t get this to work, the confirmation dialog was not opening because JS error ‘get_attributes’, the dialog element was null.
But then I turned the safe-mode, check if it was working and everything was updated automatically. I turned off safe-mode, went back to my theme and again, all was working as intended.
So safe-mode fixed it I guess. And there is no more JS error mentioned above. (Should have tried with safe-mode in the first place, smh).
Thanks for your help!