I'd agree that it looks like a materials issue.
When you see polyurethane used for intakes in FRC, it's much more often in
this form (McMaster #9697K138 or similar). Yours is a bit softer than the softest tubing, which also likely has something to do with it (in general, softer polyurethane/rubber/tread material wears faster). If you go down the polyurethane tubing route, I'd probably suggest the 1/2" ID tubing for Tetrix tubing, but it will be tight. Best of luck!