New players have a tendency to ignore the beat, and focus on playing notes in rapid succession.
I suggest a simpler approach -- stick to just ONE note -- the root (1) -- until you're in sync with the beat.
Next add in the 3 and the 7 -- but stick to the beat.
Try syncopating your rhythm -- but stick to the beat.
Explore the other notes -- try improvising briefly on the 3rd and 4th beats of the loop - but always go back to the beat.