Question Wordpress permalinks not working with Varnish

[Lethalmiko]

I installed Varnish in a Docker image using Plesk CPanel on a WordPress website with pretty permalinks enabled. I used this guide:

Varnish for WordPress in a Docker container

Want to improve the performance of your site and WordPress servers? Varnish cache can help and can be configured directly on Plesk. Learn how.

www.plesk.com

When I click on any link to an article or category, I am redirected back to the homepage with a question mark inserted and the rest of the URL. ie

Example Domain

example.com

instead of

https://example.com/news/world-leaders-to-meet/

Everything works fine when I disable Varnish. I even tried cloning the website to a subdomain and permalinks work on the subdomain with Varnish enabled. I have disabled plugins and it makes no difference.

What should I do to fix the problem?

Contents of default.vcl (with fake IP address for host)

---
vcl 4.0;
import std;

# MAIN CONFIGURATION
backend default {
.host = "123.123.123.123";
.port = "7080";
}

# ALLOWED IP OF PURGE REQUESTS
acl purge {
"localhost";
"127.0.0.1";
"172.17.0.1";
"172.17.0.2";
"123.123.123.123";
}

#THE RECV FUNCTION
# Happens before we check if we have this in cache already
sub vcl_recv {

# SET REALIP BY TRIMMING CLOUDFLARE IP WHICH WILL BE USED FOR VARIOUS CHECKS
set req.http.X-Actual-IP = regsub(req.http.X-Forwarded-For, "[, ].*$", "");

# FORWARD THE IP OF THE REQUEST
if (req.restarts == 0) {
if (req.http.x-forwarded-for) {
set req.http.X-Forwarded-For =
req.http.X-Forwarded-For + ", " + client.ip;
} else {
set req.http.X-Forwarded-For = client.ip;
}
}

# Purge request check sections for hash_always_miss, purge and ban
# BLOCK IF NOT IP is not in purge acl
# Enable smart refreshing using hash_always_miss
if (req.http.Cache-Control ~ "no-cache") {
if (client.ip ~ purge || !std.ip(req.http.X-Actual-IP, "1.2.3.4") ~ purge) {
set req.hash_always_miss = true;
}
}

if (req.method == "PURGE") {
if (!client.ip ~ purge || !std.ip(req.http.X-Actual-IP, "1.2.3.4") ~ purge) {
return(synth(405,"Not allowed."));
}
return (purge);
}

if (req.method == "BAN") {
# Same ACL check as above:
if (!client.ip ~ purge || !std.ip(req.http.X-Actual-IP, "1.2.3.4") ~ purge) {
return(synth(403, "Not allowed."));
}
ban("req.http.host == " + req.http.host +
" && req.url == " + req.url);

# Throw a synthetic page so the
# request won't go to the backend.
return(synth(200, "Ban added"));
}

# UNSET CLOUDFLARE COOKIES
# Remove has_js and CloudFlare/Google Analytics __* cookies.
set req.http.Cookie = regsuball(req.http.Cookie, "(^|;\s*)(_[_a-z]+|has_js)=[^;]*", "");
# Remove a ";" prefix, if present.
set req.http.Cookie = regsub(req.http.Cookie, "^;\s*", "");

# For Testing: If you want to test with Varnish passing (not caching) uncomment
# return( pass );

# DO NOT CACHE RSS FEED
if (req.url ~ "/feed(/)?") {
return ( pass );
}

# PASS WP-CRON
if (req.url ~ "wp-cron\.php.*") {
return ( pass );
}

# DO NOT CACHE POST AND EDIT PAGES
if (req.url ~ "(wp-admin|post\.php|edit\.php|wp-login)") {
return(pass);
}

# DO NOT CACHE SEARCH RESULTS
if (req.url ~ "/\?s\=") {
return ( pass );
}

# CLEAN UP THE ENCODING HEADER.
# SET TO GZIP, DEFLATE, OR REMOVE ENTIRELY. WITH VARY ACCEPT-ENCODING
# VARNISH WILL CREATE SEPARATE CACHES FOR EACH
# DO NOT ACCEPT-ENCODING IMAGES, ZIPPED FILES, AUDIO, ETC.
if (req.http.Accept-Encoding) {
if (req.url ~ "\.(jpg|png|gif|gz|tgz|bz2|tbz|mp3|ogg)$") {
# No point in compressing these
unset req.http.Accept-Encoding;
} elsif (req.http.Accept-Encoding ~ "gzip") {
set req.http.Accept-Encoding = "gzip";
} elsif (req.http.Accept-Encoding ~ "deflate") {
set req.http.Accept-Encoding = "deflate";
} else {
# unknown algorithm
unset req.http.Accept-Encoding;
}
}

# PIPE ALL NON-STANDARD REQUESTS
if (req.method != "GET" &&
req.method != "HEAD" &&
req.method != "PUT" &&
req.method != "POST" &&
req.method != "TRACE" &&
req.method != "OPTIONS" &&
req.method != "DELETE") {
return (pipe);
}

# ONLY CACHE GET AND HEAD REQUESTS
if (req.method != "GET" && req.method != "HEAD") {
return (pass);
}

# DO NOT CACHE LOGGED IN USERS (THIS OCCURS IN FETCH TOO)
if ( req.http.cookie ~ "wordpress_logged_in|resetpass" ) {
return (pass);
}

# FIX CLOUDFLARE MIXED CONTENT WITH FLEXIBLE SSL
if (req.http.X-Forwarded-Proto) {
return (hash);
}

# IF THE REQUEST IS NOT FOR A PREVIEW, WP-ADMIN OR WP-LOGIN THEN UNSET THE COOKIES
if (!(req.url ~ "wp-(login|admin)") && !(req.url ~ "&preview=true" )) {
unset req.http.cookie;
}

# IF BASIC AUTH IS ON THEN DO NOT CACHE
if (req.http.Authorization || req.http.Cookie) {
return (pass);
}

# IF YOU GET HERE THEN THIS REQUEST SHOULD BE CACHED
return (hash);
# This is for phpmyadmin
if (req.http.Host == "pmadomain.com") {
return (pass);
}

# STRIP OUT URL PARAMETERS THAT LEAD TO MULTIPLE REDUNDANT CACHING
if (req.url ~ "(\?|&)(gclid|utm_[a-z]+)=") {
set req.url = regsuball(req.url, "(gclid|utm_[a-z]+)=[-_A-z0-9+()%.]+&?", "");
set req.url = regsub(req.url, "[?|&]+$", "");
}
}

sub vcl_hash {
if (req.http.X-Forwarded-Proto) {
hash_data(req.http.X-Forwarded-Proto);
}
}

# HIT FUNCTION
sub vcl_hit {
return (deliver);
}

# MISS FUNCTION
sub vcl_miss {
return (fetch);
}

# FETCH FUNCTION
sub vcl_backend_response {
# IF NOT WP-ADMIN THEN UNSET COOKIES AND SET THE AMOUNT OF TIME THIS PAGE WILL STAY CACHED (TTL)
if (!(bereq.url ~ "wp-(login|admin)") && !bereq.http.cookie ~ "wordpress_logged_in|resetpass" ) {
unset beresp.http.set-cookie;
set beresp.ttl = 1w;
set beresp.grace = 3d;
}

if (beresp.ttl <= 0s || beresp.http.Set-Cookie || beresp.http.Vary == "*") {
set beresp.ttl = 120s;
set beresp.uncacheable = true;
return (deliver);
}

return (deliver);
}

# DELIVER FUNCTION
sub vcl_deliver {
if (obj.hits > 0) {
# IF THIS PAGE IS ALREADY CACHED THEN RETURN A 'HIT' TEXT
set resp.http.X-Cache = "HIT";
} else {
# IF THIS IS A MISS RETURN THAT IN THE HEADER
set resp.http.X-Cache = "MISS";
}
}