tocateclas That’s funny, my HX issue also manifested this so that may offer a clue or validation as to the cause. So when my HX solenoid was buzzing (hard), I would shut the brewing off. Then I’d try again and I’d get what you described: a surging pump spin, well above the profile and dangerously close to my aftermarket gauge’s limit. I would shut it down immediately (again), and then it would brew without issue (no buzzing, no pump overrun). I have the whole thing on video, too!
Once I shut off the HX feature, the buzzing issue went away, but then a week later I experienced JUST the overactive pump issue. Very weird. I’ll keep an eye on it to see if it returns and how often.
So long as the machine lasts a few years, I don’t mind these electrical issues too much. If they cause the machine to wear out prematurely though, that would be a whole other story.