Did you manually add a route between the two subnets on openwrt?

On openwrt? No. The routes are on my zerotier settings.

0.0.0.0/0via 192.168.192.1
192.168.1.0/24 via 192.168.192.1
192.168.1.0/24 (LAN)
192.168.192.0/24 via 192.168.1.1

If you have made settings on zerotier's server console, you also need to execute a command on the client (mainly openwrt) to tell the client to accept the routing settings push from the server.
I remember this command seems to be
zerotier-cli set Your-zerotier-ID allowGlobal=1