I've a problem with tech research. I think that it began when I changed computer and used large maps but it could be since the "megastructure" dlc (both happened at the same time) Or it happened before but research was much faster on smaller maps and I never noticed. The problem is : when I select a "big" tech (more than 20 weeks long) in one of the 3 "faspath" slots, first it starts normally with the reduced length but some turns later it reverts to the "normal" length, say from 23 weeks remaining to 49.  Quite disheartening.