no worries bro,I didn’t help much,you solved your problem.
I don’t know about this.but I guess it’s probably the assets haven’t been baked.I met it sometimes but didn’t pay much attention on it.
you could try to package the project so it bake everything automatically.but you’ll have to choose a good time to experiment with so.because it takes pretty much time packaging 
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and the particles.I like to disable their light effects (if they have).a lot of particles from market place have light effects. disabling the light increases pretty much performance to me. but all depends on ones needs,aesthetic, etc 