You should add a settings menu in PowerApps to chooce the default language for design view and formula's. Now the languages is adjusted by the standard region languages which gives all kind of problems. For example:
in European languages the formula seperator is ; instead of ,
Formula's sometimes stop working correctly when the separator is changed based on language. (Search Formula is an example)
You have to change the language back to Englisch and build control again to let it work again.
I want to be able to work in my language by default and change the languages in the applications in which I'm programming solutions. Programming I always do in Englisch.
By the way - Using the englisch URL like posted in some other threats doesnot work in this case, because as soon as you open the powerapp for editing it chooses the default languages.