When did you encounter this issue? I know there were some issues yesterday that TheDude fixed. May have been related to that. I would recommend trying again. Otherwise can you share what the size of the image you are trying to upload?

there is a 1inch inwards recess

Yes but I could not find any that are recessed. The closest thing that I found was this https://www.amazon.com.au/Smart-things-Flush-Mounted-Connection-sCh-12W-8pin-1-0A/dp/B082B7RZ5H but I can’t find something similar in Canada or USA

This is what I was thinking of as well. In the picture i included in the original post I have a red rectangle block. This is where I intend to mount the tablets. This means that I don’t have all that much space to add this hub behind it.

I was looking for recessed usb outlets but they dont seem to make them. The only thing i was able to find what a recessed housing where i could then add a usb outlet. You know of any that are a 2 in one?