Just as an experiment you could try thinning the juice or using less viscous juice. Unfortunately, PG/VG ratio is only part of how viscous an eliquid is. Different manufacturers will thin the VG with distilled water to different ratios. A 65/35 can easily be just as thick as a 50/50 based on this variable.
I would also try letting the atomizer soak in the tank for a solid 20 minutes before use the first time and see if this resolves the issue with your current juice. Although it does sound like you have probably primed/waited before.
Juice higher in sugar/darker juice often does seem to foul atomizers much sooner as well.
I don't have any sweet juices or very dark ones, all are very light juices.