I’m working with a fresh install of QGIS 3.0.3 on Ubuntu 18.04 and am not able to get my XYZ Tiles to render. When I add an XYZ Tile to the Map View it doesn’t appear. When I look at the XYZ Tile properties they look normal, as if the coverage was part of the project. If the XYZ tile is the first coverage that I open in a new project the project projection is set to the tile’s projection.
Although it’s quite possible that it’s a user problem, I followed several tutorials and the process seems quite simple. Any suggestions on ways to fix this or troubleshoot are welcome.

CRS: EPSG:3857 Pseudo Mercator
I’m not sure what you mean by: “Can you give a sample of the first dozen or so rows in your question”.
– Ned Horning Jun 05 '18 at 13:49