Random lines are appearing when I export a layout with luminosity

[NiamhMcLaughlin]

Hi, I'm currently using Arc Pro version 3.2.1. When I change the layer blend of my base map and hybrid reference layer to luminosity, random lines (which seem to be duplicates of my layers) are appearing. This only happens when I export the layout with the luminosity layer blend. I have exported my maps this way many times without an issue, however in the last 2 weeks the layouts seem to be glitching. The image below shows this. The more transparent random lines are not there until I export with luminosity. 

[AdrianWelsh]

Have you tried clearing the display cache? I am not sure if that will help or not but go to the Project tab, then Options, and under the Display section, there is a button for Clear Cache Now