A few days after delivery, I noticed something like that. I realized that the clear tape meant to protect the plastic was still stuck on one side. Whoops! Luckily, I managed to peel it off from the corners, and now the buttons are working perfectly!
On delivery day, I drained every last drop of that water by running my washer pump until it was bone dry. Since then, it’s been smooth sailing - no issues with regular washer fluid, and I’m using it every single day!