Have you tried Reaper? I haven’t personally used the experimental Linux builds, because I depend on a lot of third party VSTs, but if it's anywhere near as good as it is on Windows/Mac it may work for you.
I haven't come across any missing functions so far, should be on par with MacOS/Windows on that. Only the Interface looks a bit old-style and seems to be the only issue right now. All the "expermiental" builds have been very stable for me on Ubuntu Studio :)
Reaper was completely solid on Linux the last time I used it. The only instability came with trying to use a wrapper to use Windows VSTs, but everything struggles with VSTs, wrapped or not.