[QGIS-Developer] Disappearing -180 / 180 longitude grid lines on certain zoom levels

[Andreas Neumann]

Hi again,

For some time already I noticed that, depending on the zoom level, the 
-180 / 180 degree grid lines appear / disappear in QGIS. This is 
unrelated to the EqualEarth projection just discussed and also appears 
on other world projections, like the Robinson projection.

Here is the testfile I used with world (countries) and gridlines: 
http://www.carto.net/neumann/temp/gridlines.gpkg

Can you reproduce this behaviour?

Any idea why this happens and how this could be fixed?

Thanks,

Andreas