Openlayers: Rendering stuck - Unable to print PDF with higher resolution

Question

I am trying to use the openlayers example to print the PDF & it is working for lower resolution prints.

I am trying to fit the map to a certain polygon extent:

         `  map.setSize(printSize);

           map

             .getView()

            .fit(feature.getGeometry().getExtent(), {

               size: map.getSize()

               });`

Maps zooms in after this call but I am expecting the map to get rendered and pass the below event but it never happens:

map.once("rendercomplete", function () {

I have multiple Vector tile layers

ol/source/VectorTile

ol/layer/VectorTile

My print size is a0. Is there any optimization I could perform to address this issue ?