I would talk to CameraQuest, they are the official Voigtlander dealer, and I suspect they would know more. They've not been making the R4A that long though, so unless the seals are actually damaged, seems unlikely they would have degraded in this time.
Easy way to check if it's the scanner, scan the negative then turn the negative and rescan. If the error stays in same area in the image it's on the negative, if it moves then it's the scanner.
The only way I think that such recent foam may have gone bad is if the camera was subjected to high heat or had something spilled on it when cleaning. Foam isn't a big deal and can be replaced easily.