knotc error: failed to connect to socket '/run/knot/knot.sock' (OS lacked necessary resources)

We relaying heavily on knotc to manage dns zones. After v2.9.5 to v3.0.0 upgrade we got socket connection error. What is strange the issue is not coming out immediately, everything works fine for 0.5-1 hour. After rollback to v2.9.6 we are good up to 2-3 hours but still hitting the issue. Systemctl tuning based on documentation didn't help.