Fans not speeding up on MBPro 2018

Hello,

recently i have noticed my MBP doesn't speed up the fans automatically.

when it's not under stress, temps stay around 40°C and fans run constantly at roughly 1300 RPM(which it's strange since before I had this problem, when the MB was cool, fans would not even spin, but they would speed up if needed). when I open stressful programs (I've tested this with a game) the fans stay at 1300 RPM with temps rising, reaching 90-100°C. I've not tested it further as I don't want it to shut down due to overheating. I recon the MBP normally should start the fans at 75-80°C.

I have already tried the following:

• PRAM reset
• SMC reset(two or three times)
• Mac Diagnostic (command+D)
• Recovery S.O.S. on OS disk

none of these attempts solved my problem or reported an error of any sort.

the fans are working correctly if controlled manually, and sensors seems to be working correctly(I use TempMonitor to check temps and it can also control the fans, but I've always kept it's fan control settings on "system").