As of Friday 20 July 2018 (Tumbleweed version 20180720-369.1) qgis started working again on both systems. I add the requested info in case you want to do a post-mortem on the bug. It contains qgis dependencies for both the working version and for 2 previous Tumbleweed versions that had a non working qgis 3.0.3 and 3.2.0.