I have two SIM cards with data bundles from different carriers. One is working fine with (WiFi) tethering, but with the second SIM card, I cannot use tethering.
Searching online, I saw that tethering can be blocked by blocking browsers' user-agent headers or alternatively, by using torrenting software headers, and other PC-related application headers. In my case, I cannot even
ping 220.127.116.11 from my laptop using the second SIM card, while I can from my Android using a terminal emulator.
The tethering problem with the second SIM card existed from the beginning. Perhaps I just loaded one web page with it (or it seemed like loading, but in reality, the browser retrieved it from its cache).
So in my case, how does the carrier block the tethering? Of course, the purpose of this question is to bypass this block. There is also the possibility that there is no block at all, but something else is causing the problem, but I am baffled because this should happen with both SIM cards, right?