mutliple pdf generation with mpdf, display utf-8 charset,
I've run into the same issue. Finally, downgrading from mPDF v6 to mPDF v5 solved the it for me.
Try to use the mode on object creation
$mpdf = new Mpdf(['mode' => 'UTF-8']);if you are sure that your html is utf-8
p.s. it looks like you are creating the object 2 times.