You might try "mismatched" but it's unlikely there's a better term and in fact, the example Answers given are all appropriate to their context.
Digress or obfuscate, pivot or approach avoidance all imply deliberate intent, which is in no way clear in the example. (Pragmatic topic loss is not something I've heard of, or follow.)
The given answers might be useless but that can't be determined from the examples.
Irritating as it is to many of us, those responses are at least as likely as "correct" statements such as "It's 3:45 pm" or "Yes, please. I'd love a cup of tea" in every-day English… Other Members might speak for other languages.
Moving to use, rather than form of language, the examples given show exactly how most people really think…
Most of us don't at all care whether the time is 5:34, but whether we have plenty of time to catch the train, or how long remains before the game starts.
Most of us will enjoy a cup of tea at least more, if not only when the host is having one.