Voice Memos editing bugs

I use the Voice Memos app to record some self-made musics. While the tracks were long in length, most of them were trails and errors and only a small part was valuable. Therefore, I would like to edit (crop) the records. However, I found that the app sometimes are a little buggy.

1. I'm not sure if this is a "feature", but at least it's quite annoying to me. The problem is that when I drag the Starting From to a point, say +3.5sec from the beginning, and then Crop the track, the Starting From cursor would not automatically reset to +0.0sec. It would stay at the same +3.5sec position instead. This is annoying to me because sometimes I want to crop the head first, and then the tail second. But the head would be cropped twice if I'm not aware of this kind of behavior.

2. Sometimes, the cropped clip would be unsavable. I said "sometimes" because I couldn't reproduce the situation yet. In those situation, the Save button just didn't pop up. Other times, the cropped clip became totally unplayable. In the latter situation, it did shown the length (03:46 for example), but the waveform (viewed from pressing the Edit button) is totally empty.