Mohalkh,
I see you are a new member, welcome.
Have only seen this once myself when using the provided charging cable. In that case, when it occured, I took it into the dealer under warranty to take a look. They said the cable was fine, the port in the car was fine, and the software was fine. They said it seemed like some moisture got into the port in the car or something happened to the electricity provided by the circuit I was plugged into.
So there are three things that could be at fault:
1. Bad cable. Check by plugging that cable into another charging outlet in a different location to be sure you are on a new circuit. It is not clear what you meant by changing charging plug by the way. If you get the same problem, it could be the bad cable but then proceed to step 2. I don't suppose you know anyone nearby with a B250e that you can try their cable?
2. Bad charging port. Check this by going to a L2 commercial charger to see if it charges without interruption.
3. Bad software/hardware. If you fail both steps 1 and 2, take the car to the dealer, have them plug it in and find out what is wrong.
Be sure you take care when plugging in that things are dry and that there is no dust or dirt in the charging plug or cable.
Let us know what you find out. If you are still under warranty, get the entire car checked out before it expires.