Recently I've upgraded my internet to 400Mbps, everything works perfectly on stock firmware, but on openwrt I'm only getting around 200Mbps with software flow offloading enabled. Any ideas how to fix it? Openwrt is way more better than stock firmware and I just don't want to go back.
Depending on your hardware revision, v1/ v2 won't do any faster even if you shove it (ath79) - and v3 (mt7621) only as long as you keep it hardware flow-offloaded (so simple firewalling rules, no sqm, etc.).