I set up the SIM to another phone and shared wifi to pinephone pro by hotspot from this phone, after that I connected my own OpenVPN and everything has worked. So I can see the conclusion the wwan0 interface (modem of SIM) doesn't work with OpenVPN, it isn't ISP case. The problem somewhere on OSI application layer, routes are correct. Also all works when I use wwan0 interface with OpenVPN in Chrome which is launching in Waydroid, it is possible not only by wifi.
P.S. Moderators rename the title to "wwan0 (SIM interface) doesn't work with OpenVPN", please, it would more correctly.
P.S. Moderators rename the title to "wwan0 (SIM interface) doesn't work with OpenVPN", please, it would more correctly.