R32C111 Timer A3 Issue

Hy everybody,

I am using a R2C111 (64pins) for quite a long time and facing today an issue with the Timer A3

I am trying to decrement this timer with a 2 Mhz clock generated from the F2n divider.

It is working fine when the value in TA3 is higher or equal to 10 generating a frequency of 1Mhz

but when setting this value to 5 for instance, the frequency is still at 1Mhz.

Is there a limitation which prevent from generating more then 1 Mhz with the timers?

Thks for your usual help,

Jean-Pierre