iPhone 4 won't restore No matter what I try, it always goes into recovery mode (Connect to iTunes screen) after restoring the device. The progress bar under the Apple logo becomes full, the device reboots, then it goes back into recovery mode. Same issue when trying DFU restore. I've tried Finder on macOS Big Sur, iTunes on Mavericks, iTunes on Windows, and 3uTools. No dice.
I got it working by using Pwned DFU Mode (iPwnder32) and idevicerestore with an IPSW.