Ditto what Larry said. I do Travis picking on guitar, which is kind of similar to banjo. I found when playing slower, if I am having a real tough time, set the metronome (MN) to beat twice (or even 4 times) the speed I am trying to play. For example, instead of quarter notes (100 BPM), set it to beat for the eighth notes (200 BPM). Then, as you get better at playing along side the MN, go back to quarters… when you master that, set it to half notes. If you really want to test your internal clock, set it to beat once a measure or once every other measure.
Another problem I have seen is when some people try to listen for the metronome and then after they hear the click, play with the beat. As a result they are always just behind it and uneven. I have to sync my internal clock with the metronome and play along side it. It’s kind of like trying to drive your car right next to another one going down the highway. If you are always looking at it and micro-adjusting, it will be constant work and your speed will always be changing. On the other hand, if you just drive your car and stay aware of the other car in your peripheral vision, you can drive a more stable speed and it’s much less work. I hope that makes sense.