iPad Pro Magic Keyboard shift key working intermittantly

I had this exact behavior and it turned out that assistive touch was turned on. Once I turned it off, everything works again.

Hi, DJKenn. 

Welcome to the Apple Support Communities! We understand that you’re experiencing an issue where the Caps Lock and Shift keys are no longer working on your Magic Keyboard, and we'd be happy to offer some assistance.

It sounds like you’ve already done some pretty incredible troubleshooting. We’d like to start here:

Does a full restart (not a forced restart) resolve, even if only temporarily? 

Restart your iPad - Apple Support

A full restart allows processes to fully shut down and boot up again; whereas, a forced restart will immediately cut the processes to your device and neglect to perform needed processing. We encourage you to only force restart your devices when you’re not able to fully restart. 

You might also check to see if you’ve inadvertently set up customized keyboard shortcuts that use either of those keys. 

Learn iPad keyboard shortcuts - Apple Support

Warmest Regards.

i also have several issues with my magic keyboard which i just purchased a week ago. the shift key has completely stopped working - to capitalize letters and also to get the ‘at’ symbol or quotes or parenthesis…this is very frustrating. also, the auto-capitalization does not work at the beginning of a sentence…i have all these actions enabled under general/keyboards. also, the tab key does not work - tab from field to field or indent. help1

Appreciate the suggestions, which I applied. Reset shortcuts to default and did full restart. Problem still persists. Whichever app is open when I attach the Magic Keyboard will have the Shift keys functional, but if Close that app or even open another app, the Shift keys do not work, until I pop the iPad off the Magic Keyboard and reattach it. It’s very odd

do your lights work,, not only has my shift key stopped working but my lights are out

I tried everything here as well, and the shift key does not work.