Impossible to delete a map

I'm trying to delete a map I created by cloning another one of my own, without any custom assets, but it won't let me. I've tried from several devices and loging off and on and have always the same behaviour: After confirming the deletion, the spinner appears, the request fails, and a message saying I'm offline appears at the top right (although the rest of functionalities work perfectly).

I've attached an image of the offline message and a capture of the request that fails.