RPM meter goes down after reving in neutral

I got a bit of an odd problem with my Daytona 675 2008.
My bike works fine and runs perfectly.
Everything looks as it should do when I turn on the ignition and start the bike.
RDP meter is looking normal. But if I rev the bike in neutral or when pulling in the clutch the needle first goes up as it should but when it goes back down it stops at about 1000rpm lower each time. After a few revs its down at 0.

Anyone ever had this?

Turning off the bike and switching on the ignition again will reset the needle to its correct location until I rev it again, and the same thing happens.
The battery is new and I have a voltage meter installed that is pinned at 14V when the bike is on (also have new regulator/rectifier and stator).
Monitoring the rpms with an ODBII scanner always shows the correct rpm readouts, so its only the instrument cluster needle that is wrong.

if I avoid revving the bike in neutral or when I have the clutch disengaged I can ride all day and the correct rpm will be shown. But if I, at any time, rev the bike when not in gear and clutch not engaged the readouts will be wrong until I turn the bike off and start it again.