I'm having trouble using marker data to specify the y height of an A2S...

I have an X spline with a marker at the very start, with a value in MarkerData 0. If I build a RC object based on that spline and attempt to get the height from the marker data via an arithmetic node I get the error "No size or spline on Y". If I evaluate the expression with PRINT instead of RETURN it gives the correct value from the marker data.

Any tips on what I'm doing wrong?

I have an X spline with a marker at the very start, with a value in MarkerData 0. If I build a RC object based on that spline and attempt to get the height from the marker data via an arithmetic node I get the error "No size or spline on Y". If I evaluate the expression with PRINT instead of RETURN it gives the correct value from the marker data.

Any tips on what I'm doing wrong?