Modpack version
1.70c

Issue
setup: make a recipe: {crafts "48 flux core" from "64 obsidian" and "64 flux"}
then build a XNET auto crafting system: the system always holds 64 flux cores, and submit to The ME network cores if it exceeds 64.

by whichever block the flux core crafted, this bug happens: TE sequantial fabricator, AE2 molcular assembler, RFtools Crafter, Mekanism Crafter....

behavier:
The Crafter Craftes flux cores normally(makes 4. 1 stays in buffer, 3 go as output.) then send them to a buffer. the Xnet Checks if the buffer's current store exceeds 64.

The magic happens here. 2 of 4 crafted cores are...just 'disappear.', resulting only 16 core, not 48 cores.
the
Logs
Input pastebin link to crash-report or latest log, if applicable

I probably won't have time to look into this to be honest, but thank you for the report.