Jonas , further to all this, I reinstalled the IBTS in an effort to determine if that as an issue. As I mentioned, previously it did not feel securing mounted (“wiggly” being the term I used), after reinstalling it 3 times. Once again after dismantling the thing, it had become looser than desirable , with light visible around the base. HOWEVER, I discovered that by using a center punch and large hammer I was able to force the two pins further into the silicone/rubber base , thereby creating a tighter, more secure mount, eliminating any light around the edges. (OK, so i didn’t really use a hammer but the center punch gave me the careful leverage I needed to force the pins all the way into their intended receptacles. ). I have done a few roasts and will report back as to whether this was the source of the problem… I am almost certain it was. I guess I exercised an overabundance of caution previously when connecting the pins. Perhaps that is responsible for the problems others have had with this also.