So i have been able to narrow it down to the companion powers causing me not to be able to switch loadouts. I can replicate it consistently.
I have a ticket submitted, but someone will probably just look at it and say to post something here, so just getting ahead of the game.
For anyone else with this issue (been nearly a year now still no fix (copying all the equipment , power selections, mounts, etc is not a fix, it's a band aid)).
What i have found is if you clear one companion power at a time, then try to switch , you will see which one is causing the issue and try to work around it.
The other really screwball thing that i found is, if i clear the power on the one loadout, switch to the other, then switch back, the slot that i left cleared gets filled by a the same power that is slotted in that position by the other loadout. The exception to that is if you have the same power in a different slot on your secondary, then it just seems to choose a random power and auto fills it in with that... So it seems like the loadouts are somehow colliding with each other, which should not be the case, they should be completely independent, so maybe the devs could just make it clear the power selections when changing the loadouts before applying the new loadouts instead of just rearranging and replacing the selections, maybe that would make this go away, finally!