Alright!

Sorry to spam here, but I think a good way to get this to behave correctly would be to make the buttons at the top scrollable. That way they'd always be available, unscaled, no matter what resolution you're working with.

Here on my phone, rotated so the "Next" button goes offscreen:

I can't duplicate this - adding references works fine and the edits show up in my history.

I don't actually think that this is a bug on the part of VE. VE just takes the template and parses it without error according to the instructions in the template's documentation. If we attack this problem from a VE angle, the only optiosn IMHO would be:

I've also been unable to reproduce this on Firefox and Chrome, both using the standard and the mobile site. Mostly I tried making edits that didn't have any effect or much of an effect. Since I can't reproduce it and the bug was apparently fixed recently, I'm closing this issue - hope I don't step on any toes in doing so.

Resolved by editing documentation of relevant template: https://en.wikipedia.org/wiki/Template:Infobox_football_biography/doc

Clarification: When adding a new Persondata template, the GUI walks you through the template creation process as expected. After adding the template it is shown as a placeholder glyph inline until the page is saved. At that point the template is properly saved.