Hi … I’ve been having problems with my Waltec shower diverter for some time now, replaced O-Ring works for a bit then slides off again. Replaced with new diverter and less than 6 months the O-ring will slip off. What is the problem with theses diverters ? …. the only way to keep it working is turn water off before pushing on the diverter, when new it worked for several years, any ideas……? Thanks.