​Dog has been eating green firm chewy foam-like material

Dog has been chewing on green object pictures.

Our 45lb dog has been throwing up (and pooping) out solid chunks of this green chewy squishy material. Doesn’t seem to be a yoga mat or a ball or something, but similar texture. Been going on for weeks now and we’ve scoured the house but can’t find it. He’s clearly chewing on it and then unable to digest the small pieces.

It’s a light green. Soft but firm. It doesn’t appear to be a yoga mat. We’ve checked all our shoes to make sure the insoles and outsoles are still there. He could be getting it from the garage or the bedroom.

The chunk pictured is less than an inch big. They’re small pieces but he’s chewing them off and swallowing them whole.

Thanks in advance!