I've found cross tubs to be much better than road tubs. I don't even mount road tubs anymore on 'spare' wheels because I find that the base tape gives way a lot earlier than the glue joint.
Been racing on cross tubs for 7-8 years now and I do not see the same thing... have no idea why. I always use Mastik One, road and or cross. I only buy top quality tubs. I find Tufo to be the best for cross, the base tape is solid and you have no tube inside to worry about. I've got some FMB's that have been mounted for two years and they are still rock solid.
Could be the original mount? You need to use a LOT of glue to mount cross tubs...