It actually does, because that helps narrow down what is going wrong to something specific in your system (not just Opus).
Not necessarily. I guess Opus and TC do not share code, so the two do not handle third-party file previewing in exactly the same way. Also, security software could simply block one but not the other due to a totally random, unrelated situation.
Yes, that is not normal. I suggest you try whitelisting Opus in your security software (most likely Defender). You could also try reinstalling Office (you did not say which specific version). If the issue continues, then you might need to create a process snapshot.