Custom supports, Tab Anti-Warping don't slice with the rest of my model?

[Balakay612 0]

Hey there. I've been experiencing this strange behavior with Cura: sometimes, the custom supports I add will slice when I slice my models; other times, they show up as nothing but an unsliced "shadow," and if I try to print the resultant gcode, it's clear Cura did not in fact create the code to produce such supports. This happens with both Custom Supports and Tab Anti-Warping. But the strange thing is sometimes, without any apparent reproducibility, custom supports will in fact slice. 

 

Has anyone else experienced this? Does anyone have suggestions on what to try next? I'm attaching a screen grab of an example using Tab Anti-Warping. When such things have worked in the past, the skirt would accommodate the space around the custom support structures; here, it's acting like it's not even there. Thanks for any advice or suggestions! I'm using 4.13.1, but prior versions have had this behavior as well.