I think, first of all you should move following filter outside the function and then check –
add_filter( 'upload_mimes', array( 'JBLAB_Utils', 'images_upload_mimes' ) );
Even if it does not work, try changing the priority of the filter.
I think, first of all you should move following filter outside the function and then check –
add_filter( 'upload_mimes', array( 'JBLAB_Utils', 'images_upload_mimes' ) );
Even if it does not work, try changing the priority of the filter.