I upgraded my Early 2015 Macbook Pro to Catalina and I can't turn on wifi. I opened Network settings and there was a button <do not loc> for a few seconds and then it changed to "Turn wifi on". I clicked on it and nothing happened. I tried restarting Mac and SMC and NVPRAM/PRAM resets but it didn't help. I also can't run Wireless diagnostics — I click on the app and a window pops up for a second and then disappears. In the Network app, the Wifi interface isn't listed in the interface options for a new service ("+" button). Could anyone please help me with this problem?
P.S. I don't have a direct connection to the Internet (only through Wifi).