This is what I've been noticing. For C++ and Swift, it makes pretty unhelpful suggestions. For Python, its suggestions are fine.

Swift is especially frustrating because it will hallucinate the method name and/or the argument names (since you often have to specify the argument names when calling a method).

Ah I've had it hallucinate non-existing methods in python rather often.

Or when I say I need to do something, it invents a library that conveniently happens to just do that thing and writes code to import and use it. Except there's no such library of course.