Since "upgrading' to PP2019 it will not play the audio in MTS files from a Canon Legeria HF G25. Had no issue (could import and edit) with this type of file in PP17 or PP18.
Solution is to use Handbrake to convert to MP4. Now video and audio plays in PP2019.
Check Audio hardware settings in Preferences.
Delete media cache,
rename top folder video is in,
see how that goes.