Set the metronome to a slow, comfortable pace.
Play just one note on each beat.
Then speed up just a tiny bit…. Feel that tense rushing.
Slow back down to the beat… Feel that smoothness.
Now slow down just a tiny bit… Feel that sluggish pull.
Speed up just enough to get synchronized again… Feel that smoothness again.
Playing in time is a matter of constantly feeling for this anxious or dopey energy and then adjusting until you feel that sense of relaxing into the beat. It’s not a thinking thing.
It’s a feel thing.