constant crashes: could m4a->wav files be to blame?

[jessup]

Hello -

ProTools crashes (with the spinning wheel of death) every time I try to cut (with either B or ctrl+E), copy, or move regions between tracks.

I've tried installing various versions of ProTools (2020.3, 2020.9.1, and now 2019.12) and even upgraded to a MacBook with more (32G) of RAM and I still am unable to edit the majority of my project's audio filles, which were originally recorded in M4a and converted to wavs. I don't have the same problem with files originally recorded as wavs.I've uninstalled plug-ins and even deleted preferences, so I suspect the files type might be the issue? The sample rate (44.1 kHz) and bit rate (16) are all consistent.

Any idea what might be causing this, and how to address it?

Thank you for any and all help.