Anonymous users created with diffrent language than project default.

In our project we have these language settings: As you can see nl_NL is set as the default. After upgrading from mendix 7.23.6 to 8.1.1 we noticed our anonymous users are being created with their language set to en_GB which is the secondary project language. Anyone else experienced this after upgrading?
1 answers

There is something in the release notes of 8.1.1 that might have had an influance:

For native mobile apps, anonymous users are now localized using the user’s OS language instead of the app project’s default language. If the user’s OS language is not recognized or not configured in the Project Settings, the project’s default language will be used.