Can't use phone hotspot

I have two phones here. Phone 1 has a chip with a data plan. Phone 2 has no chip. I enable the Wifi hotspot on Phone 1, connect to it with Phone 2 over WiFi and Internet works just fine on Phone 2.

Now, when I connect my Linux desktop to Phone 1 over WiFi, it connects but Internet doesn't work. I can't ping any address. Any explanation for that? Maybe something wrong with the routing?
TIA