Question about Xiaomi Air Pump

...I tested the pump for the first time today and had the same problem. Have you found a good solution in the meantime, or is the "mess" with the flat nose pliers the only option?

I had this problem once. I then tightened the inner valve more firmly with a pair of flat-nose pliers. After that, the inner valve got stuck when I unscrewed it. So far I have had no more problems with the pump. It is in constant use. We have 6 bikes.
I wouldn't want to do without the pump on our bike tours.

... You have to tighten the Presta valve a little more than you would by hand with a valve spanner so you don't overtighten the valve and it doesn't turn when you unscrew it .....

I have the same problem. Unfortunately, I haven't found a solution yet.