Two mikrotik with default gateway

MT1 192.168.255.1

MT2 192.168.255.5

DHCP server on MT1.

I can access the Internet from the MT1 router itself.
I can access the Internet from the MT2 router itself.

The client 192.168.255.130 pings both MT1 and MT2

Work on MT2 SOCKS5 !!!

But if default gateway 192.168.255.5 (MT2) - everything dies.

And ...?

Do you want advice on your configurations?
Then post them BOTH, instructions here:

Need more info on your setup. But just looking at what you posted. 192.168.255.1 is the default gateway not 192.168.255.5