Underextrusion issue - Vcore 3.1

Lately I’ve not been able to get a clean print out of my ratrig, it is severely underextruding every couple layers.

Material is Bambulab matte blue PLA printed at 200 degrees with a Rapido 2 UHF at normal speed. I’ve taken apart the extruder, cleaned the gears, fitted a new nozzle, tried different temperatures, but the issue still prevails. Is the hotend thermistor defective?