Wrestling with some ridiculous Play offline bounce stuff right now as well, not the exact same issue but with a similar solution (disabling streaming from disk). I threw HWS spiccatos into my template to use for layering in an upcoming project, and while testing everything out started getting pops and clicks in any offline bounces. The best part is it's not even all of the patches-- it is specifically happening with the viola, cello, bass spiccato patches. For example, the viola staccato patches offline bounce fine!
This was originally happening in Logic, but I verified the same behavior in Cubase 10 with the Play VST. I tried hosting Play in VE Pro as well-- same exact behavior, pops in clicks on the same patches with offline bouncing. I even completely re-installed HWS just in case.
Disabling streaming from disk fixes the problem, but as Peter pointed out this incurs ridiculous RAM usage once you have more than a few patches loaded.... luckily I think I will get away with keeping just the HWS spiccatos I need in my template and take the RAM hit, but it has made me think twice about including any EW Play products in the future.