If the bubbles dissipate quickly, it may be a normal/minimal amount of residue creating them.  Plus, there's a lot of churning going on so it may not be suds at all.  They don't call it white water for nothing in recreational rafting circles.

If the suds were more persistent, I'd say you might have a rinse aid dispenser leak.  On my KDI21, something seemed to be happening with the rinse aid and when I filled the glass carafe for the coffee maker after it had been through the wash, I'd get bubbles on the water surface that wouldn't go away.  I had to rinse the carafe out any time after it had gone through the dishwasher.  I'm fairly certain it was an issue with the rinse aid dispenser, but we soon sold the house and left the machine behind so I never pursued it.

Yes, very little rinse aid is required.  We have fairly hard water here, and I have my Miele DW set for the least amount of rinse aid to be dispensed:  1ml.

I run the dishwasher once or twice a week.  The Miele has an indicator that lights when the rinse agent reservoir is empty.  It took a year for that light to come on after filling the reservoir when I first got the machine.