Of course, it would be dumb to post a proof, but just having to take your "long time expert veteran" word for it is good enough.
I don't doubt you are encountering an issue. But your assumption that it is a magical Construct 2 bug rather then something not coherent in your code is what bugs me.
I have been using C2 for the double of your lengthy experience, and I still prefer to think that my code is at fault when encountering an issue.
And guess what, in most case it is. And when it is indeed a Construct failure, I do make a bug report, following the report guidelines to make sure.
But your advice here is "don't doubt your code, blame a magical bug and do nothing about it".
By doubting your code that's how you get even further in depth into C2 and go from the intermediate user that you are to the expert that I dare to say I am.
And if it is actually really a C2 bug, it would help every one to have it fixed and so to provide some code for it.
At worst you can post your code "privately" to Scirra directly. But tbh, it is more likely there is an issue in your events then a bug with the local storage that worked now for years...