Hi,
This appears to be a glitch associated with version 15.0.0 because in version 14.1, when I try to switch on transparency in the Fit Y by X platform while being in Fast marker drawing mode, JMP returns an error message telling me that transparency can not be turned on in Fast mode.
I believe that there has been a couple of updates since version 15.0.0, hence I would recommend upgrading (if it is an option for you).
Otherwise, you may need to stay away from the Fact drawing mode when generating plots for export.
Best,
TS
Thierry R. Sornasse