RockPro64 Fan Control

I know there are a ton of fan control posts related to ATS, but I don’t have anything ATS installed. I have a RockPro64 with the latest DietPi installed. I have the 10mm heatsink with PWM fan installed as well. In previous months/years, I controlled the fan speed with /sys/class/hwmon/hwmonX/pwm1 and a simple bash script running at boot. Recently, that stopped working. Well it continued to work, but only for a second or two. Then the fan would spin down and stop until CPU temps hit ~60C or so and then start to ramp up automatically. While this sounds like an ideal situation, any load produces fan surges and it idles in the ~50C range. What is taking over hwmon/pwm?