I work with a team of illustrators using templates that we've built in Adobe Animate for publish to Canvas. On a layer we label as controls, we create a combination of Graphic symbols and strokes. The strokes are 1 pt. and 1.5 pt. solid and dashed lines (4 pt line 3pt gap).
At some point, the strokes convert to fills. It occurs inconsistently and unwantedly. We have not been able to determine what causes this to occur, but it is not due to accidentally applying convert lines to fills. We have already ruled this out. It only occurs on the layer labeled controls. We are currently changing this to cont, but it is a naming convention that makes sense to us, so we'd prefer it to remain.
Note, this template did not behave this way in Flash CS6 or earlier.