Shadow not much to report, unfortunately. There is a know bug in the open source Telegram library I use. It has been discussed on the internet, but there is no permanent solution available, unfortunately. It still exist in newer (unstable) versions of it. I tried to debug and patch that library myself, but so far had little progress, as it has pretty complicated asynchronous architecture, so it is extremely hard to figure out how it works and why it don’t in some cases. There is one workaround though, one user reported it worked for him.
The core of the issue
Telegram has multiple servers around the world. Each time client connects to Telegram network, it connects to nearest server to speed up communication. However, those servers are not always identical. For some reason (probably this has to do with GDPR or other similar legislation) some servers cannot authorise some users. And when this happens, they redirect user to correct server that can. Same thing happens when for example one server does not have some image, it redirects client to other server that has it.
However, this “redirect” works OK for downloading images (I tested that many times), but for some reason it fails during user authentification. However, this problem is quite rare, as in most of the cases, when you try authorise in your own region, the closes server to you is the right server already, and no redirect is necessary, and it just works.
So in your case, you are probably located not in the same region where your phone number was registered initially. One user reported that he had successfully overcame this issue by tricking Telegram to think he is in his home region, and therefore connecting to the right “nearest” server right from the start. He has done that by using VPN to change his “virtual location” to the correct region.
Please let me know if does make sense to you. Do you have possibility to use VPN on your computer for the time of authorization in Telegram?