Statistics update slowly

While the scoreboard statistics update immediately after e.g. mining a block, the ones at ESC->statistics take a few seconds to update.
This time seems to be in game ticks, because having the statistics open (therefore pausing the game), then shortly exiting and re-opening the statistics doesn't give the updated value, only having the game running for a few seconds updates it.
Tested with: dropped, picked up, mined, used blocks.