I have the same issue with upright bass, was reminded in a master class video by Carlos Henriquez that you really need to work on developing even tone between your two fingers, consistently alternating on open strings at 60 bpm starting with quarter notes working up to sixteenths . I've been working on it for a few weeks and making progress.
When I was primarily a bass guitar player, I found that "Bass Fitness - an Exercising Handbook" by Josquin Des Pres was really helpful. 10-15 minutes per day of consistent right hand practice (alternating index and middle finger) made a huge difference for me, as well as increased left hand strength/dexterity. Find it on Amazon.
When I was primarily a bass guitar player, I found that "Bass Fitness - an Exercising Handbook" by Josquin Des Pres was really helpful. 10-15 minutes per day of consistent right hand practice (alternating index and middle finger) made a huge difference for me, as well as increased left hand strength/dexterity. Find it on Amazon.