# If you are using a PiAware sdcard image, this config file is regenerated
# on boot based on the contents of piaware-config.txt; any changes made to this
# file will be lost.
Note the "If".

Maybe you just didn't save the file when editing it? (in regards to the ppm setting)

The settings from piaware-config in regards to dump1090-fa normally have zero effect when not using the piaware sd-card image.