Random curved edges missing in LayOut

Two parts are fine, this and one other part are missing curves. Help please.

I have used another instance from the SU drawing with the same result.
I have added the curve in Layout and it is still missing when exported as a DWG.

Update 2:
I have added all four parts to the one scene, and the same result occurs in layout - two ok and two with some curves missing.

If you share the file we could probably help you better.

Can’t do that. I realise that makes things difficult, but can’t be done.

It appears there’s some limit to the radius of a curve in layout - even though half of the curves were ok.
I have redrawn one shape, and got the same result - but eliminated the issue by increasing the radius of the curve.
These are factory drawings requiring some .4mm radius corners, so this is not acceptable
Does anyone know if it is possible to make any adjustment to the tollerances.

Solved - reducing the number of segments on the curves in SU did the job. (Still the anomaly of why some worked and others not.)

Very small edges cause problems in SU. You can often do as you did and use fewer segments for small arcs or cubes to prevent attempting to create edges that are too small.

You can also scale up a copy of a component in SU (commonly by 100 or 1000), draw or edit the large copy, and the original sized one will be edited to match.

SketchUp can shrink larger edges but not create them at very small sizes.

Search this forum for “Dave method” attributable to @DaveR (Dave Richards).

I use the Dave Method often. SU wasn’t the problem, the issue was with LayOut coping with the segment number. The bizzare thing was, when I added the missing arcs in LayOut they didn’t appear in the DWG file either.