dishwasher never stops :(!!!!!

Hi,
i am new to the forum and thanks in advance for your help.
I have a Kitchenaid dishwasher model : kude20fb bs1.
What happens if whenever un do a normal wash or ‘‘prowash’’, the cycle never ends and wash for hours without going into drying mode.

Last time, i started it at 10pm, went to sleep, and at 6 a.m in the morning it was still running.

I tried using the "1 hour wash" mode, and it works just fine, goes to dry mode without any problem.

Anyone know what causes the problem?
Thank you