iPhone 7 Plus stuck in recovery mode and can't restore/update even in DFU after downgrading from iOS 11 Here is what has happened. I'm hoping there is still hope in me fixing this since the weekend is here and the earliest I can get a repair appointment is Monday.

I've been on the iOS 11 Developer Beta for about two weeks now. This morning I decided that I was going to downgrade back to iOS 10. Followed all of the instructions and in a few minutes, my device was being "updated" back to iOS 10.3.2. This is where everything went wrong.

I leave the phone and come back about 20 minutes later to see iTunes says that my phone is in recovery mode and needs to be updated or restored. I click on "Update" and it fails and says it needs to be restored. So this time I click on restore, it goes through the whole process and iTunes says that my phone has been restored and it is currently restarting. However, as soon as it restarts I get the same damn prompt again telling me I need to restore or update.

I do this about 4-5 times with no luck. So next I decide it's time to put the device into DFU mode. Even when my phone is in DFU and I try to restore it to the most recent iOS 10 update I am getting the same problem. iPhone restarts and says I need to connect to iTunes and it's in recovery mode.

Any suggestions? I'm going crazy trying to figure this out.
I would avoid DFU for figuring out what is wrong - it's kind of a last ditch effort to revive a device without a lot of diagnostics or error reporting. Since Apple restricts who can receive betas and asks them to communicate with users on the various seed and beta discussion groups - many people here will decline to engage on beta discussions so you might get better answers on Apple's forums devoted to the beta programs.

Also - since you know the firmware is on iOS 11 at this point, why not try reinstalling iOS 11 again to see if the device is still working?

Foregoing that, what happens when you plug the device into iTunes and attempt a restore? 

That operation is designed to log error conditions, statistics, reasons and many items to log files. From there you would benefit from being able to reach out to Apple support and also have a large audience with experience in restore errors. It could be an unlikely hardware failure or a likely firmware issue where you are now committed to running the beta pending some changes to the software either on the iTunes side or on the iOS side to allow you to go backwards in code version.

If other people have this issue, I would suggest asking a new question with specific details like - what version of iTunes and what OS (Mac or windows) and what specific error message you get before you try DFU. As you have acknowledged in the post - recovering from DFU failure is usually with Apple Certified technicians and/ or hardware replacement assuming your PC/Mac and iTunes isn't the cause of the restore issue.