PHPSpreadsheet 1.15.0, access cell by name

Question

I have an Excel "Template" with some named cells as "student" for example, which is the cell coordinates B2 I used to use PHPSpreadsheet and access some cells by: $worksheet->getCell('student');

It worked until the last 1.15.0 version, which returns me this error: "Fatal error: Uncaught Error: Call to a member function getCell() on null" In my Excel file this named cell is "=Feuil1!$B$5", but if I try to manually change it to "=Feuil1!B5" I have some stranges behaviours, the named cell place change for C5, or B4, etc...

I really need to access cells by name by I don't know how to do this with the 1.15.0 version of PHPSpreadSheet...

Thanks!