I can't believe you mentioned ISO. I wiped down with ISO yesterday before spraying some Stynlyrez white, and fisheye discribes just what I got. Also, I did some prepping with Mr Surfacer 1000 and forgot that ISO attacks that stuff too, which baffles me.
I use the Badger mixer and have only recently started mixing Stynylrez with it due to troubles. You mentioned globs, and that describes what I'm getting. I can't say the Badger stirrer does or does not solve the problem.
OTOH, I used primarily Stynylrez grey for years with no issues. Could spray forever, no dry tip, no stoppage. I recently tried a thorough stir with the Badger stirrer (with the grey). I think it helped, but did not solve the issue. This is why I have new (smaller white/grey/black with a gloss black on the side on order.
We should stay in touch on this as it sounds like we might be having similar issues.