I have a .htaccess file for an apache server that works perfectly on all of my apache servers, but breaks on the ionos shared hosting server.

I will explain how to reproduce the issue with 3 files.

File 1: Here is my ~/tt/.htaccess file which has just 3 lines.

RewriteEngine On
RewriteBase /tt
RewriteRule content index.php?resource=content

File 2: Here is my ~/tt/index.php just to print out request variables:

<?php print_r($_REQUEST); ?>

File 3: And I made a dummy ~/tt/content.a.php that just holds this text.

hello world

Next, I put this code on my lamp server. When I visit https://mypersonalserver.com/tt/content, I successfully see the output Array ( [resource] => content ) .

Next, I put this code an ionos shared hosting server. When I visit https://ionosservernamehere.com/tt/content, I see this result here

If I change the file ~/tt/content.a.php to ~/tt/content.p.php on the ionos shared server, then I get the same Array ( [resource] => content ) output.

Why does ionos not like the letter a in the file name ~/tt/content.a.php?