I rarely use SC to attack, so I've never experienced this in PVP. I don't know what can be hapenning, but during some heroic defenses I was unable to deploy my SC troops to defend my base. I click, click, click to deploy and it does nothing. It hapenned not one, or two, but several times, so I stopped request troops or trying to use SC troops only for HDs while I can win the Bronzium Crate only with Armory turrets and GR, maybe one or two heroes.
A Windows survivor now training players and helping squads through the Galaxy!
Imperial HQ10 in "BombSquad18" (Level 49 squad)
Rebel HQ10 / HQ8 in "Ewok_revenge" (Level 50 squad)