Some times its because of a miss timed RT call.
Would be interesting to know PPrune radar if the crew co-ordination repeats are after certain linked events.
ie decent to an altitude shortly followed by a vector or direct.
Or initial decent followed by the same.
About 90% of the times I have asked for a clearance to be repeated its because a checklist has been triggered by the previous instruction and just as the PNF gets into the guts of it another instruction comes in.
It could be as simple as doing the direction changes first then the altitude change or just leaving the direction change for 60 seconds after the decent.
And 10mins to landing is always a good one, as one of you is on the PA normally.