Editable Patch object get selected through another object

[Anonymous]

I created a tire with a line and a Lathe modifier applied to it. Then, I converted it to an Editable Patch. I changed its shape through sub-object mode, and now this object always get selected whenever I left-click on an area that contains it, no matter if the object is in front of other objects, or it's hidden behind them.

For example, if there's a box there that covers over a tire, when I try to select the box, I always have the tire selected, not the box.

Does anyone have an idea what is causing this issue?

[Anonymous]

Are you sure other objects aren't frozen?  Usually frozen objects appear gray in the viewport, but if that option is disabled, then it won't be noticeable. 

[Anonymous]

Yes, completely sure.

I've just tried again. I've created a simple tire and a box in front of it. I've noticed that if I enter, e.g. vertex sub-object mode of the Editable Patch and then exit it, everything will be fine. But when I make some changes to the geometry using handles sub-object mode, or even just click on patch sub-object mode and do nothing - the issue will occur again. I haven't tried anything more than that, though.

That's weird to me, because I'm learning with a Digital Tutors course, and the instructor doesn't have this issue as I can see throughout the course.