Not even sure if this is a bug - maybe there is some global event or some other race's ability that is causing my ships to .. malfunction in this way but -
I built ships with 2-warp IV drives.
Speed should be 9 (or more from my various upgrades/tradegoods/hyperion shipyards blah).
When the ships are first created, it shows 9/5 Moves Left. So that seems about right - 9 movement. Ok. It's cool. No problem. Every other turn after however it is at 5/5 movement... ???
I am not in the area of influence of the Yor (Super Isolationist) - when I do enter their area my speed is reduced to 3/3 - but anywhere (and I mean anywhere) else all my ships are built and can move 9 on the first turn.. then only 5/5 on the next turns.