Resolve 14.1.1 Rendering Problems

Ok, maybe I'm missing something or doing something wrong be here I go. I'm on Windows 10.

Why Resolve is not respecting my mutted tracks when rendering video + audio and is rendering all tracks? A bug or me being dumb?
I noticed that with the betas and now I still dont know if its a bug or a missed setting.

Why sometimes I cant select any track, only some are available, when choosing and Output track > Timeline track for rendering?
I dont know what I did but it became selectable when I created a new track but when I had only 2 tracks, only the first one was selectable for rendering a timeline track. I restarted, changed from mono to stereo and back to mono and the only thing that worked was creating another (unecessary) track. I was going that path as a workaround for the first question.

Another thing I'm seeing now:
I'm rendering to DNxHR 444 12 bit. When I render a single clip, it renders fine (video wise). When I select multiple clips, it doesnt respect my changes do the clips speed, it renders at the original speed.

I looked for a checkbox or setting but couldnt find any for that.