How large is the map frame - in page units? Are you zoomed into the layout page?
Tom
Chris what resampling is applied to the raster in symbology? And what version of Pro are you on?
ArcGIS Pro 3.4. I think it may be due an issue with resampling. See attachment. The classification is based off the air photo imagery you see in the background 0.6x0.6m, so both rasters should share equal cell dimensions. The air photo uses Nearest neighbor and appears fine, ALTHOUGH it does display at a reduced resolution when you uncheck/check the layer in the Contents panel. To get it back to its original form, in Layout view mind you, I have to uncheck/check the classification layer. Weird... The only way I was able to get the classification layer to display properly was to use Majority resampling.
Chris,
Apologies for the delay I was working at the Developer and Technology summit last week. Can you please call or email support and give them a project package of the case you're able to reproduce this problem with? We definitely want to take a look and see if something is going wrong at the raster renderer level on a layout.
Haha, no worries. Yes, I will do that. Thank you
There is a known GPU driver error when using DirectX 12 in many Intel GPUs in the last couple quarterly releases. It could be related to that. @JeremyWright provides great information and details about how to resolve it in this community post https://community.esri.com/t5/arcgis-pro-questions/layout-not-rendering-properly/m-p/1590837#M93570