Seems there is a bug with equipment weight at mission start.
2 cases of same loadout (anu assault legs, golem body, eidolon helm + gauss heavy + synedrion sniper), with only one difference: 15/16 weight vs 16/16 (extra sniper clip).
16/16 works as it’s supposed to.
15/16 get -1 extra movement. If I drop anything and pickup during mission I get correct max movement.