Catwalk bug + alien disk bug

The physic engine of the game is a bit off. My trooper walks into a factory and wander around until he spot an alien on the cat walk. He had enough TUs for me to run him under the cat walk for cover from alien's next turn. The very next turn the alien shot at my trooper through the catwalk! Ok so plasma weapon willl cut through earthly materials, I guess I will buy that for immersion sake. The next turn, i have my trooper (assault) run out in the open and return fire. The shotgun blast suppressed the alien... and also blast the catwalk from existence... but the alien did not fall from it. It just stood there in mid air... is this a known bug?

I encountered the alien disk thing for the first time today. It shoots a hail of plasma at my trooper and ducks away. On my turn, I have someone shoot at the disk and my turn is frozen. I can select different trooper but i cannot command them to do anything. I end up having to click end turn and watch as the disk unload another hail of plasmas killing most of my troops. After that the combat runs normal again... Not sure of the sequence this happens and so was not able to replicate.