Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 431.36
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: rBf6cb5f54494e
Short description of error
[using an external cache in 2.8 is broken, cached system nothing like what was baked]
Exact steps for others to reproduce the error
[Bake the attached scene to a disk cache, it should still work so far, then chose 'external' option in cache panel & load what you just baked: bingo!
If it's anything like my result you'll get 3 particles, rather than the 20 in the original.
Images of this process attached.
I first noticed this when trying to get particles from a 2.79 scene to 2.8 (blame the latest Fracture Modifier tutorial!);
a particle system emitted from one static mesh, living longer than the total scene frame range, and all borne over 3 or 4 frames from 2.79 (which read the cache as external perfectly), then tried to load it in 2.8: all over the place! Popping in and out of existence, totally different timing & dying way before the end of the frame range (and a different number of particles as well, as in the attached).
I am getting this in Blender 2.8, 2.81 & the Mantaflow 2.81 version as well]
Trying to use the cache as 'external'-