Here are some suggestions for debugging W3 applications:
If it seems like the w3-param command is not working correctly, that might be because the same-origin policy is preventing query parameters from being parsed. Try adding the w3-allow-xorigin-parameters command to the top of the page generator proc, at least temporarily, to see if that clears the problem.
If parts of your webpage do not appear to be working, that might be due to the restrictive default Content Security Policy (CSP) that W3 uses. Try temporarily disabling the CSP using a command like
w3-content-security-policy off
near the top of your page-generator proc.Temporarily insert the output of the w3-debug-env command in your output to see what is going on. Example:
w3-trim { <h1>Environment</h1> <pre>%html([w3-debug-env])</pre> }