@t109598044 you may try to rebuild the kernel with DHT11 support, unless done already.
I do not have right now tx2 to test with,
but make sure you are setting/using the correct pin
for 37 on tx2 I seem used gpio388 GPIO26 on j21 header
you seem using pin 18 gpio296 of jp21, right?
reference https://www.jetsonhacks.com/nvidia-jetson-tx2-j21-header-pinout/
unless the pin defined in software matches the wire connection ther ewill be no signal. you may also like testing with multipleter/ logic analyzer is there is a current from the sensor in given situation
However after each change in the file C_DHT.c
there will be a need to rebuld the app with the build command from the quote below
sudo python setup.py build
sudo python setup.py install
in order for changes to take effect