Alternately, perhaps you should play the 5 more. It really depends on your long-term goals.I don’t. I have four string that has been my steady player for over twenty years. Due to our band learning more material actually written in century, I had to get a 5 string. I’ve tried for the last year and a half of just using the 5 string. The fact is after numerous gigs rehearsals and practice sessions, all recoded and reviewed, I am not as good of a bassist playing a 5 string.
So, I will be swapping out basses from here on out.
I transitioned from 4- to 5-string. About three years later I transitioned from 5- to 6-string. My perception is the transitions degraded my playing and it took about 2 years to get back to where my playing was before each transition. For context I was a full-time pro during these transitions.
I also think it took me about a decade to really feel like a naturalized 6-string bassist. Prior to that, I approached the 6-string like a 4-string with a few extra strings. What do I mean? The number of strings on the bass has some impact on fretboard logic and which patterns of fingering and shifts are optimal. With a 4-string you have to shift up and down the neck more. With a 6-string, it often makes more sense to play across the strings and shift less.
For the following reason, I prefer to play 6-string pretty much exclusively. If I play a 4- or 5-string for even an hour or so, I starts modifying some of the automated processes I use to play. The result is it starts to degrade my fluency on the 6-string. At this point I am far more confident on the 6-string than on a 4- or 5-string.
That is not to say I can't switch between 4-, 5-, and 6-string, only that doing so incurs a cost. I prefer to avoid the cost, so I don't spend very much time on my 4s and 5s.
I concede that there are probably some things I can still do better with less string. However with exception of the first few weeks of transitioning to 6-string, I don't believe I ever reverted to 4-string because I couldn't get the job done perfectly well on the 6-string. At this point, overall I am strongest on the 6-string...it's not even close.