Frame 0 or 1 inappropriate 'spurt' of particles / file attached

I’ve got a cylinder that is Booleaned w/a “pizza box” cube, as an emitter. Particles should only be emitted from the intersection of the cylinder and pizza box, and this is true for most of the animation.

EXCEPT, on frame 0 (or 1) there’s a short spurt of particles from the origin of the emitter (see image). Particles are set to emit from VOLUME, and there’s nothing there at the start of the animation, so I’m not sure why this would be happening, except that it’s a bug, something like the Boolean isn’t evaluated at frame zero or something.

Am I doing something wrong, or should this be submitted as a bug? I’m thinking it’s something simple, like order of evaluation.
200727_MoreTest_3.blend (1.5 MB)