Can't ssh to a local machine.

[evgeny71]

Hello everyone!
I am very new to networking and can't figure one issue
I'm pretty sure it's because of the lack of my knowledge and need help.
My setup:
Version: OPNsense 21.7.7-amd64
OPNSense router on (generic) mini-PC -> network switch -> local network, wireless mesh and WiFi extender (Netgear router running OpenWRT).
Some devices, including the extender, have static ip's. I can ssh to a media server which is another generic mini-pc with static ip, running Linux, with no issues. But I can't ssh to the extender. Every time I try to access that device, I get a login prompt of the main router (OPNSense). With my previous setup on LinkSys WRT1900ACS as main router I could access that extender with no issues. The only device that is different since then is the main router itself. I haven't used the extender's ip in any settings or services on the new router, except DHCPv4 as static lease. All the static IP's from the same IP range.
If I try to traceroute to any other local IP, it finishes in 1 or 2 hops, but traceroute to this IP never succeeds.
Any help is appreciated.