How to fix Valkyrie A360 throttling in Remnant II combat?

After long combat sessions in Remnant II, the Valkyrie A360 temperature rose abnormally, dropping the frame rate from 120 to 90 FPS. I first tried restarting the system, which temporarily lowered the temperature but the problem persisted. I then used the GamePP Hardware Sensor to monitor water cooling liquid temperature and pressure, identified a slight air blockage, and performed an air purge. HWiNFO monitoring showed the temperature dropped from 85°C to 75°C.