Issue mod_pagespeed not being applied to old sites only new ones

[Twincarb]

As per the title, I have mod_pagespeed installed and when I create a new domain or subdomain then the pages are rendered with the expected coversions css into 1 file js into 1 file, jpg's coverted to webp format etc.
When I look at domains and sub domains that are older they don't have the same modifications applied, mod_pagespeed is running on them because various elements are showing pagespeed is looking at the page.
There are no custom pagespeed rules in any of the sites, I thought it may have required the configuration files to be rebuilt, however this doesn't change the observed mod_pagespeed behaviour.
Any help would be appreciated in getting the older sites working as expected.

 

[dopeboy]

can't really help about this because i use pagespeed for nginx i'll just tell you about my experience with pagespeed

in some sites it works in some it doesn't in some combines files in some nope you'll have to try debug ?PageSpeedFilters=+debug

 

[Twincarb]

Thanks for the pointer @dopeboy just incase anyone else faces a similar issue I have added some more information below.

Add ?PageSpeedFilters=+debug to the end of the url your interested in, or any on the domain and have a look at the produced page source code, ?PageSpeedFilters=+debug will add comments into your html to be able to see why pagespeed was unable to apply the transformations that your expecting.

The culprit that I had was within my .htaccess file preventing mod_pagespeed from doing its stuff

<IfModule mod_headers.c>
    Header merge Cache-Control "no-transform"
</IfModule>

Rather than removing the above lines from the .htaccess I added the following line to the Additional directives for HTTP/HTTPS

APACHE
ModPagespeedDisableRewriteOnNoTransform off

If your using NGINX the following would be required in the NGINX directives

NGINX
pagespeed DisableRewriteOnNoTransform off;

After this rechecking the page source code will show if things were successful or any further issues

 

[dopeboy]

yes i was asking for that because well without some logs no one here can help you doesn't matter how much knowledge or experience they have always keep that in mind when you search for help give as much details as you can