Matt Brooks on 24 Jan 2025 20:24:26
The gridlines always disappear on the first small multiple box of any line, bar chart, or column chart where small multiples are used.
The only way to get the gridlines to return temporarily is to click some other slicer value and then click it back to the value you had. This refresh action will get the gridlines to return as long as you never touch the chart. If you then touch the chart in anyway, the gridlines will go away again.