Audio Express. unexpected behavior.

original file
144p, 49mins, mp4 with audio, 35MB

trimmed to
2mins 45s, mp4 with audio.

no additional scene or audio added. just trim it to a shorter one.

once downloaded the trimmed, it's 157MB....

several issues here:
1. a 144p source is recognized as 1080p
2. trimmed file (less than 10% length of original) results in a 5 times larger of original file.
3. first 1 second of trimmed file has audio distorted