Did you calibrate correctly? By default the values are veeery low, the PID is too agressive for managing very low temps and very low power. ( Mine barely hits 260 at 450°C setpoint).
Also the T12 can't measure below 90-100°C so if your calibration is wrong weird things will happen.
I have seen that behaviour on said conditions, and it's normal because it's not set up correctly.
Anyways, when it starts oscillating, lower the PID.
I can't magically make it working for a controller I don't have!
Was this problem on the latest firmware?
Otherwise, don't ask for issues happening in older builds!
My controller works perfectly fine, I've used it for the whole morning (5+ hours non-stop) with perfect results.
At this stage, with such weird issues happening only on (v2.1 ?) boards, I can barely do anything, because it needs deep debugging on affected hardware.
Consider crowdfunding to buy a ksger 2.1 controller so I can properly develop for it.
Otherwise, to me it's blindly guessing what it could be.
I will check the ioc files to ensure the peripherals, interrupts, etc, are set correctly.
Tugo, is your's a v2.1? No problem trying 72MHz -once-.
But I can't manually maintain and build 3 Ksger boards and 3 mcu versions each, every time!
I ran my quicko at only 8MHz, and it did perfectly fine! Only had increase the ADC time to 1000uS instead 350 due the much slower clock.
I guess the display DMA helps a lot. But the display works completely smooth, even the temp graph, everything! Only the scrolling was a little less responsive.