I downloaded Arcgis pro 3.4 earlier this week and there seems to be an issue exporting maps to pdf. I have a setting for the basemap to export at 50% transparency and with this latest version of pro this setting in the pdf export is not coming through. The images have the basemap at full opacity. I hacked my way around this issue with a white polygon overlay but then now I have random layers that are turned on and in the legend but the features are not showing up in the pdf export.