I always had modem in bridge mode, then use my own router for changing mac and ip, now I left modem in router mode so maybe that's why new mac on router doesn't give me new ip

A MAC address is a hardware encoded address. You can't change it. Maybe using bridge mode changes the way your ISP assigns IPs. But I doubt it. I think the ISP changed their system.

All working now, as I suspected issue was modem not being in bridge mode, now that it is.. works like a charm, every time