Hi all,
a quick note: be extra careful when updating an iPhone in recovery mode.
I just wanted to update my iPhone (that was still stuck in boot loop) to the latest iOS 13.3. As several times before, I put the iPhone in recovery mode, iTunes opened automatically to state that there's a problem with my iPhone and that it requires to be updated or restored and, of course, I clicked on "update". Then the usual warning message appeared that I'd need to restore the iPhone if the update failed. iTunes downloaded the new iOS. During the download, the iPhone suddenly left recovery mode and started to boot. So I put it back in recovery mode. After iTunes finished downloading, it started to update my iPhone, or so I thought. In the message pane at the top, it showed "Restoring iPhone software". I thought "that's strange" and I should have aborted this process immedately by rebooting my iPhone but I didn't grasp what was going on. Just when the "Hello" appeared on the screen of my phone I realized that something had gone terribly wrong.
So, my iPhone was restored instead of updated.
This wiped all data from my phone and also all my hope of recovering my data. 😢
PS: of course, it's now out of the boot loop, but that's not what I wanted.