How to set ping to modem in VPN?

Question

Network routing

Raised VPN 192.168.50.0 between vps on the Internet and the home network
Pings back and forth as it should, including the router and home computers. (192.168.1.1-255)
The router has a USB modem E3372 Hilink 192.168. 8.1 - before it there is no ping at all.

ip route

default via 185.188.xxx.1 dev eth0 onlink
185.188.xxx.0/24 dev eth0 proto kernel scope link src 185.188.xxx.xxx
192.168.0.0/16 via 192.168.50.2 dev tun0
192.168.50.0/24 via 192.168.50.2 dev tun0
192.168.50.2 dev tun0 proto kernel scope link src 192.168.50.1

What can be wrong? Already tried different settings on the openvpn server and in the routing router - to no avail.
Ping from computers to the modem goes, from vpn does not go ((