Originally all the limit switches did not have a membrane stopping water ingress. The Titan limit switches look exactly the same but include the membrane and so do all the new limit switches for the other machines. They are awkward to replace after the fact this is how I did mine.
At the time I ended up having to replace the limit switch with one from my pro limit switch kit. Now I have a bag of the limit switches with the membrane so anytime I get a failure with the old switches never replace them out with the new version. I’ve never had a new version of the limit switch of the membrane fail.