Some objects have hitboxes that are very hard to select when trying to interact with them. For example, a gate on the northern end of Cernaya (near the fire station), or various objects on or under shelves. It often takes a minute or two just to open said gate or pick up an object, leaving the player exposed for an unnecessary amount of time.

Similarly, I've come across multiple objects that I simply couldn't touch, no matter how long I tried. In Nova, for example, there were arrows on top of a set of lockers (above head level), and I couldn't reach them. I'm not sure if this is the same problem as the one above or not.