Try this –
Right click on a clip (you can do this in batches as well).
Go to MODIFY -> AUDIO CHANNELS.
set NUMBER OF AUDIO TRACKS to 2,
CHANNEL FORMAT to ADAPTIVE,
click PRESERVE CHANNEL ASSIGNMENTS,
ACTIVE CHANNELS PER TRACK TO 1
Set SOURCE CHANNEL LEFT to Audio 1, Ch. 1
Set SOURCE CHANNEL RIGHT to Audio 2, Ch. 2
Then save the preset. Don’t ask me why or how, I’m a PPr newbie myself. I do have a pretty good background in audio editing and this was driving me crazy as well. I’m sure a veteran will have a better answer.