Sentinel-3 OLCI FR pixel size

hi,

Is there a way to keep Sentinel-3 OLCI FR original pixel size (270m) when exporting it to Geotiff?

When I open the exported sentinel-3 OLCI FR in QGIS the pixel size is approximately 350m.

The pixel size is not constant over the image. The 270m refer only to the nadir line. So I think the resolution is preserved.