Just to draw some extra focus to one thing that EJ James said above, I strongly suggest using the System Parameter Reset! I moved to 18.04 when it first came out, and it sounded killer on a few of my patches, but some of the others just didn't do much for me. I just assumed I needed to go in and tweak the problematic ones. After reading that a number of respected folks had used this reset function, and how almost everything was great again, I wondered if there was a chance that mine could actually need this, even though a few of my patches were stellar. Long story short, I finally decided to give it a try, and damn! Now all of the patches sound great. So, from my personal experience, I think it wise to give that reset a try, even if a few of your patches are already good. YMMV.
Cheers,
Lee