These Card Visuals have the same X-Position and width, but don't allign visually as seen in the image.
The bottom card appears to be one pixel further to the right.
When it happened last time, swapping their positions solved the issue.
This happened using PowerBI Desktop (July 2019, 64 bit version)
Please update Power BI desktop to the latest version 2.72.5556.801 then test again.
Best Regards,Qiuyun Yu