Particles not rendering properly

Just recently during the times of the TP woes that seem to be upon us, I also noticed that particles now look as tho they are going on and off. I get great billowing clouds, then none and then billowing clouds again where I used to get constant particles.

This is only the case with steam or fog emitters that emitt a high number of particles at a time.

I have my preferences set to ultra with particles at 8192. It happens not quite so badly at 4096 but still happens.

I have a very high end system and haven't changed anything.

Anyone else ever run into this?

Appreciate any help folks can give me.