Is it a bug or not?
With all the improvements of Musescore 3.6, which I really appreciate, there is, what I'd call a nasty bug.
When creating a new score, so far Musescore offers no way to set "swing"-settings. You have to add it afterwards. That's O.K! However, when I save my individual style settings (with the "swing" attribute), and later on reload it to a new score, the "swing" is automatically set to "on". But the "swing" attribute is not shown, despite it is active. From mere looking at the score, it looks like a "straight" setting. No great problem with a new score, for you realize it when listening for the first time to what you have input.
I saved my personal new 3.6 style settings (with "swing") and later applied it to older scores prior to 3.6, which so far had a straight attribute (actually it means: no attribute at all was to be seen, neither "straight" nor "swing"). Only after re-uploading some scores withe the adapted 3.6 style-setting, I noticed by chance, that they suddenly replayed in "swing", which spoiled the tune.
As I wasn't aware of that issue I had saved the new style settings without naming the style file as "with swing" and when applying it to the older scores I was not conscious of every single individual setting that was contained. I was in good believe, the style still would be "straight", as nothing other did show up.
That's no coherent behaviour! If Musecore with standard-setting from the very beginning applies a "straight" style without explicit indication and applies a "swing" style only when explicitly assigning it to a note, then I expect the same behaviour with a saved style setting. That means when a loaded style set contains a "swing" style with the first note it has to be explicitly shown above this note!!!
Moreover, there is no possibility to set neither the "swing" nor the "straight" attribute in the style dialogue, it only can be done by explicitly assigning the respective attributes from the text palette. Therefore it would be ok, too, if the "swing" attribute would never be saved with the settings at all. Either so or the other way. But not as it momentarily is the case.
Please do correct this quickly. it is a nasty trap other users may tread into, too.