Hello ,
Your landscape resolution is going to be affected by the texture resolutions within your landscapes material as well as the Static Lighting Resolution you have applied in the ‘Lighting’ section in the details tab of your Landscape Actor. You can modify the tiling of your textures so they don’t appear stretched out which can sometimes cause your textures to appear blurry.
Could you provide me with a screenshot of your Landscapes material and of the details tab for your Landscape actor within the level?
Thanks,