Starting with Affinity 1.8, path points are missing if they're "back-and-forth" movements.
Say we have a path and in that path we have a Point A and move to Point B. If we set Point C somewhere inbetween and move back there after Point B, Point B will be missing. In the attached image strip file, the leftmost line of the second icon (the "fax machine") will not be exported to SVG because of this issue. Taking a look into the SVG code, the point is simply missing in the path.
Affinity 1.7.3 did export that line when I exported the very same file. My issue is 100% reproduceable and happens everytime under the above circumstances (move from A to B to C where C is between A and B). I think it's a bug because the SVG looks different than what you see in Affinity.
6014_EditbuttonsAdressen.afdesign