Hi again, Frank2, and thanks for your response and clarification.
Please, rest assured, your concerns are NOT odd - not at all! It's commendable that you are trying to learn as much as you can about this condition and how it affects you in particular. Keep in mind, this is not a 'one size fits all' disease - COPD affects everyone differently. It can even vary in how it affects you from day-to-day. For example, one day, you might become short-winded doing an activity, while the next day, it you might not become as short of breath. This can be the very nature of the disease.
Based on your expressed concern about various oxygen (saturation) levels during different types of exertion as well as remaining at rest, I thought this article might explain just how this can happen: https://copd.net/clinical/breathlessness-vs-oxygen-saturation/. I do hope this material sheds some light on this aspect of the condition.
Warmly,
Leon (site moderator COPD.net)