Scatterpoint invisible if colorAxis is present and value is NaN (even when markerfill is set)

[Spordoz]

Steps to reproduce

1. Create a model
2. Add axes (including a color axis)
3. Add scatterseries which uses said color axis (renders fine) (actually set the colorAxisKey)
4. Set value of all points of scatterseries of step 3 to match them to a color in colorAxis (all points have a value between min and max of the color axis)
5. Add scatterseries which sets .markerfill instead (don't set colorAxisKey)
6. Do not set value of points of scatterseries of step 5 (value is NaN)

Platform:
.NET version: .net742 and .net7.0 (tried on both)

Expected behaviour

Oxyplot plots the series using the markerfill value and ignores the value of the point or coloraxis since it doesnt need it.

(this image is after I have set all points to a value (0 in this case)

Actual behaviour

The scatterseries of step 5 will now be invisible. Selectable, but invisible.
The moment I give these points any value at all they are rendered

As far as I know value of a point shouldn't play any role if markerfill is set. But the moment I give it one (the value does actually not matter, the resulting color is always the same (markerfill color). Setting the InvalidNumberColor value of the color axis does nothing.

[VisualMelon]

Does the color axis InvalidNumberColor change anything?

[Spordoz]

It seems I never finished that sentence. If I remember correctly setting LinearColorAxis.InvalidNumberColor changed nothing.
It shouldn't even be concerned with the colorAxis if Series.MarkerFill is set if I understand the code correctly. So maybe it is indeed ignoring the colorAxis and thus LinearColorAxis.InvalidNumberColor, but it is also ignoring Series.MarkerFill as long as no ScatterPoint.Value is set (NaN).

Edit: Just tested, LinearColorAxis.InvalidNumberColor indeed does nothing. Tried setting it on every other colorAxis and even making a seperate color axis that has it set specially for the NaN series.

Edits: Edited for clarity