I believe Jon's advice is excellent, and I would be surprised if it doesn't help you. But, after applying the CA glue test/fix, should you still find your UST wanting, consider that we often assume routed saddle slots are dead flat, and that is often not the case. We also assume that there is consistent quality control for all Under Saddle Transducers, and they all output evenly across their length, and that is also not true.
Short of replacing your pickup, there are a couple of additional "tricks" that can aid in the proper fitting of a UST and, rather than write it all again, I will link to some very valuable information contained in the LR Baggs Element Installation Manual, located
here (as of the time of this post).