Front wipers stuck on low when in gear

Hi everyone,

Have an odd problem, and I have searched the forums without avail. I have a 2010 santa fe limited, 4 cyl auto. The multi function wiper switch operates perfectly when in park, high-low, wash, intermittent, etc. When the vehicle is put into gear (as soon as you move the selector) the front wipers come on in the 'low' setting. The multi function switch does not work except to select between high and low when you're driving. It's not a big deal, but it's fairly annoying.

I changed the multi function switch (thought the wiring in it might be bad). same symptoms

I changed the wiper motor (thought the park switch might be bad). no change

I have unplugged the (what I assume is the auto moisture sensing plug) from the windshield. no change

Tired of the embarrassment, and of buying wiper blades.
Also getting tired of buying extra parts that I might not ever need.

For the meantime, I have fashioned a 'kinda ghetto' power interrupt switch, but I'd really like to fix it correctly. any ideas?

thanks in advance for your time and expertise.