The culprit behind JuliaDynamics#1045 was the use of poly! for user defined polygons. As a first step, I replaced it with 
`scatter!(p, p.pos; p.color, p.marker, p.markersize, p.agentsplotkwargs...)` and generating the plot with the custom polygon worked. In that case I think the whole if else statement is no longer necessary so I removed it.

```
if user_used_polygons(p.agent_marker[], p.marker[])
poly!(p, p.marker; p.color, p.marker, p.markersize, p.agentsplotkwargs...)
else
scatter!(p, p.pos; p.color, p.marker, p.markersize, p.agentsplotkwargs...)
end
```