iCloud restore on new iPad Pro stalled/very slow.

After restart, the "estimated GB remaining" has gone down to 13.7, but apps still don't seem to be downloading, and while my internet is plenty fast that I should have seen that "remaining" drop by now, it's not dropping.

Alright, it has now been overnight. More than eight hours later. It is down to 1.8 GB remaining.

My internet connection is fast enough that this should be done by now. Just since waking up, I dowloaded 15 GB of files on my Mac, over the same WiFi and internet connection, and it took less than 15 minutes. There's no reason the iPad Pro should be this slow.

Well, a further 8 hours, and it's been stuck at 1.8 GB remaining the whole time. I have restarted twice during that time, it has been plugged in to power the whole time, my internet has been working fine the whole time. Heck, I even plugged in a USB Ethernet adapter that is supported by iPadOS to make sure WiFi wasn't the problem. The fact that it did ~12 GB in 8 hours overnight, but hasn't budged the last 8 hours shows this isn't "just keep waiting" or "slow internet". A 4.5 Mb/s internet connection would have finished the last 1.8 GB by now. And mine is far faster than that.

I have, still stuck on 1.8 GB 12 hours later. I really want to get this updated to the latest iPadOS to be secure, but it won’t let me until the restore is done.

Another 12 hours have passed, I've let it sit multiple hours, restarted, let it sit multiple hours, etc. Still stuck at 1.8 GB remaining.