In general, we avoid the "best" discussions cause best is very subjective, and very few people substantiate a claim with facts. After all, what might be best for me, might not be best for you so... what is best after all
Not going to tell you a specific OS, but for most professional setups, when stability is far more critical than features, etc, LTSC 21 is the way to go. Which LTSC of the ones we have here, doesn't really matter as the core is always the same, so just go for the looks you like, or extra software that is maybe included.
Other than that, OS are free here, so try a few and see which one you may like more but please avoid using lite ones, because since they have a lot of components removed, some demanding audio software might not function as expected.
Nothing else to add, so the thread will close.
Hope it helped.