Not sure if it's a bug or working as intended, but enemies can attack Mykara units after teleport button has been selected, but before destination is chosen.

AutoSave 919.sav

AutoSave 920.sav

There's a single harmonite collecing temple ruins. If you select him and queue the teleport before the AI attacks you will see (920 is the most recent, I included 919 in case you can't get all the steps done after the load, before the attack).

Thanks for the feedback, hope you are enjoying the expansion!

As for this behavior, this is not a bug, the attack order locks the armies into battle as soon as the target was selected, moving the attacking army next to its target is mainly an animation process, if you did not finish the teleport order (by selecting the target) before getting locked into an attack, you cannot avoid the combat