When pressing on flaps control to increase flaps position from 0, flaps speed in the indicator is normal, takes a few seconds to go from 0 to 1.

If, during this time, you use the flaps increment controls once again, the indicator jumps really quickly to 1 and then to 5 not respecting any timings. I couldn't see this behaviour from 5 to 15, to 20 etc, only from 0 to 1 then 5 if you act on the controls quickly.