I am also having this exact issue.
Running Jupiter8V2 version 2.5.4 (latest)
Pro Tools HD 10.3.6 (latest)
Session is 24 bit 44100 kHz
Mac OS 10.6.8
Pro Tools HD2 hardware with 192 audio interfaces.
When I reinstate the plug in it plays in Stereo for a minute or two, then goes back to left channel only.