The pattern should continue unchanged in those bars. For fun I did a Spotify search, though, and found a couple of recordings by well known names where the bass line, played by an organist in one case and a pianist in the other (both are bass less recordings) goes up a fourth, so I guess it's up to what you like. To me that unchanged bass part under the IV chord is one the things that makes the tune so beautiful. As a self- described jazz novice (me too, for life!) this is the kind of thing you need to start hearing. Relying on and trusting your ear as opposed to getting stuff off lead sheets and the like will help you enormously. I bet you heard that line unchanged and didn't really trust your ear and figured it must be shifting to conform to what your preconception was. It's also an interesting example of how context and expectations can influence what you hear. For example, when I tune up I sometimes mis-hear the string I'm tuning because I hear it resonating with another string, rather than really hearing how it relates to the reference I'm trying to tune to.