Things to consider:
1-What is the exact format of the audio on the ZOOM? Maybe try making the PT session at the same sample rate and bit depth?
2-Can you simply copy or move the audio from the ZOOM to your computer? I would do that and then bring into a PT session with the File>Import>Import Audio command(I have also had Drag & Drop not work enough times that I simply don't use it and stay with the Import command)
