Column headers disappear when scrolling horizontally

I've got a table with column headers in a report. All the column headers have a green background.

Because they contain sensitive data, I had to blur the actual names and values. You can however still see where data was available and where the column headers were present.

When I horizontally scroll through the table, there are some points where the column headers disappear. These points are always at the same place. This only happens when viewing the report at PowerBI.com, not in Power BI Desktop.

The gaps between columns are all the same measure that always shows an empty value (and are used to have visually blocks of columns). Could this have something to do with it?