2 accounts - language does not stay set by default.

I had already passed that you should be able to change the language per location, now this is not possible. I then created a 2nd profile for my client and where he can set his language to "French". But however when he logs in to his Dutch-speaking account, logs out and then logs in to his French-speaking account it always comes up in the Dutch language. If he does this in another browser there is no problem. In Belgium it is usually bilingual, so now I have to create separate accounts for many companies, but that the language changes when you do this in the same browser, I would like to see fixed.