Suddenly access denied cUrl in PHP - php

Question

I used the following function to get access to an API (live working example)
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://www.halteverbotszonen.com/api/numbers');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.0.3705; .NET CLR 1.1.4322)');
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
$output = curl_exec($ch);
$status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
Since a few days (can't tell exactly when) it gives me a 403 error when executing the curl call. Accessing https://www.halteverbotszonen.com/api/numbers directly is possible. I have not changed anything on any of the two servers, what could possibly cause this and where could I see that (any logs for this?)
I have a second api where the same happens (accessible directly works, but not via curl call).
It's the same hoster, could they have changed something that does not allow incoming curl calls?
Any hint appreciated

Answer 1

- Maybe due to https/http ?
- Maybe a different conf inside your apache/php ?
- Maybe the distant server banned your IP
:o
In most of cases, when something works and PAF another day didn't work anymore, it's a software update problem (like conf file) or network problem (like IP) or distant problem (like the server). I guess :D