When exporting a product the file name of this product is used as suggestion for the new file name. Which sounds good in the first place, can be inconvenient for some products, like the Sentinel products.
This behavior results in suggestions for
Sentinel-1: manifest.tif
Sentinel-2: MTD_MSIL1C.dim
Sentinel-3: xfdumanifest.nc

Instead of the file name the product name should be used. This product usually has a meaningful name.