I am not sure if something has changed at some point in one of the recent patches, but tried playing some Adaptive maps with the dynamic mex spawn options, and we're running into issues --
Trying to set up unused spawns to not spawn core mexes, but the random spawn option seems to be randomizing ACU location after the mex spawns are determined. It never used to do this. (We used to very frequently play 8-player "Phantom Fortress" map with 6 or 7 players, and the empty slot(s) would always reliably be the only to spawn with no core mexes).
Take any Adaptive Map that allows for "Used Slots" selection under "Dynamic Spawn Of Resources" option.
Turn on Randomize spawns
add less than maximum players.
Start game: ACUs will randomize, but core mexes appear to were enabled.
Not sure if there' s a fix needed or if I am overlooking something. Let me know if I can give more info.