I don’t have the answer but much the same my cadence is generally a bit higher indoors, around 100 and averages 90 outdoors, both feel comfortable in their own right.
What I have found though is that I am more comfortable spinning a higher cadence outdoor when necessary, little surges where I don’t want to change gear, that type of thing.
There was a study that found untrained riders were wasting energy by spinning too high, IIRC, here’s the article, cba re-reading it