ERR_TOO_MANY_REDIRECTS on WordPress
Why it happens on WordPress
WP_HOME and WP_SITEURL set to https:// while a proxy passes the request as http:// makes WordPress redirect endlessly trying to reach the scheme it already thinks it is on.
The fix on WordPress
Add the standard HTTP_X_FORWARDED_PROTO check to wp-config.php so WordPress detects HTTPS correctly behind the proxy, and confirm both WP_HOME and WP_SITEURL use the same canonical hostname.
Is ERR_TOO_MANY_REDIRECTS happening on your domain?
The uptime probe returns the full redirect chain, so you can see the exact two URLs bouncing off each other instead of inferring it from behaviour.
Free, no signup. Runs from outside your network, which is the only way to tell a server fault from a local one.
If that didn't fix it
WordPress has its own failure mode, but ERR_TOO_MANY_REDIRECTS has a wider set of causes that apply everywhere. The most common one overall is: the cdn forwards to the origin over http while the origin redirects all http to https — an infinite loop.
All causes and fixes for ERR_TOO_MANY_REDIRECTS