The issue still the minification unfortunately. I cannot re-create the issue with the core W3TC plugin, as it works correctly – I use it on the demo site as well, it is great.
However as I mentioned earlier, the two very important global variables are moved by the minification script to the site footer, into a custom function. Please take a look at this, this is from your site footer: https://i.imgur.com/WNUNR95.png
These variables have to be outside of any function, and currently they are encapsuled within the window.w3tc_run_foot() function, which is causing the problem, as the ASP and the ajaxsearchpro variables become local and no longer accessible outside the function, as they should be.
This is not caused by the search plugin, it is very likely a customization, the code originally works fine as well as with the original W3TC minification script. There is nothing I can do about this, as it is caused by customization, which moves the search variables to a function scope, making them local, which is incorrect. Localized variables should not be removed from the window's scope.Best,
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