Just adding a reply to follow this issue. I had the same issue as well when upgrading from 21.7.3 --> 21.7.4. Very slow web interface and noticeably increase CPU usage. Reloading 21.7.1 seems to have resolved my issue. I didn't know about the revert command.
Run bare metal on a Supermicro X10SLH-N6; E3-1270v3; 16GB with an Intel X520-DA2 card added as well for the LAN side.
Run bare metal on a Supermicro X10SLH-N6; E3-1270v3; 16GB with an Intel X520-DA2 card added as well for the LAN side.