cpu stuck at 1600mhz

I have an Acer Aspire 5 with i5-8250u mx 150. My CPU is stuck at 1.58 Ghz. I tried to fix it with intelppm from regedit by setting the start value at 4, but it just got it to 1.80 Ghz. It was working at 3.40 Ghz. Is it the bdProchot? I didn't use it at heavy task so I don't think it was...