Does this count as a 'leaf'

It reads to me that the OP has used an acoustic caulk as a panel damping material and on the other side used a panel damping material as an acoustic caulk.

Sorry for any confusion and thanks for following up. I am talking about caulking the gaps around the edges of plasterboard sheets - with caulk - fire-rated/acoustic caulk. Which is basically designed not to shrink/ crack over time. And my query is that the GG caulk/ they call it GG sealant, is shrinking where the sikkens and CSR did not...which has surprised me because I thought all things GG would be top notch. And wonder if there is some particular trick to using the GG sealant? I have contacted GG but not heard back yet. (And I do have my GG NON sealant tubes all ready to go for use BETWEEN the sheets.) P

"And my query is that the GG caulk/ they call it GG sealant, is shrinking where the sikkens and CSR did not" I guess I would have stayed with what was working and would continue to get in contact with the GG reps, if you suspect that you are having a material failure. I would think this is not common, the failure. Now there can be circumstances (freeze/thaw/extraordinary heat) that can reduce almost any type of caulk to junk. I am not saying this is your situation only that in transit(the delivery) of these materials the climates especially at this time of year can fluctuate wildly and could have affected your material, or something within the environment. You have to look into these things forensically to make a determination. The information will help to better your case in divining to whom blame should be placed, IF indeed there is blame to be placed at all. Keep us in touch with this concern if you will.