Ubuntu – Lm-sensors stops reading temp1, causes overheating

Once in a while, after waking my laptop from sleep (a Lenovo Thinkpad T440 on Ubuntu 18.04) lm-sensors will fail to read temp1 and as a result, thinkfan seems to think the temperature is low and does not start the fan. There are other temperature readings still available in sensors and I see the temperature of some getting as high as 80C. Restarting the PC often does not solve the problem, but shutting it down and turning it back on will most often do it. Anyone ever had this kind of problem? This is what the output of sensors then look like this

    coretemp-isa-0000
Adapter: ISA adapter
Package id 0:  +43.0°C  (high = +100.0°C, crit = +100.0°C)
Core 0:        +41.0°C  (high = +100.0°C, crit = +100.0°C)
Core 1:        +42.0°C  (high = +100.0°C, crit = +100.0°C)

thinkpad-isa-0000
Adapter: ISA adapter
fan1:           0 RPM
temp1:         N/A
temp2:         +0.0°C
temp3:         +0.0°C
temp4:         +0.0°C
temp5:         +0.0°C
temp6:         +0.0°C
temp7:         +0.0°C
temp8:         +0.0°C

Edit:

$ ps auxc | grep -i therm
root       154  0.0  0.0      0     0 ?        I<   May26   0:00 acpi_thermal_pm
root       956  0.0  0.0 186996   420 ?        Ssl  May26   0:01 thermald