Strange Bosch Dishwasher not draining but also draining!

I have checked all the normal stuff, blockages, hoses, filters etc.

Dishwasher will run a cycle, but at the end not finish and pump out. It will keep running.

If I reset and interrupt I can run a manual drain and the water will pump out no problem. But for some reason will not at end of cycle. any ideas?

Bosch Dishwasher, 15yr old. SHV45M03UC

thanks in Advance