And using this online tool Rex Swain's HTTP Viewer with the input URL of http://climatech.ps/.well-known/acme-challenge/somtestfile I see
This problem case:
with a User-Agent of "Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)" this:
Rex Swain's HTTP Viewer
http://www.rexswain.com/httpview.html
Code last updated 5 August 2023
Request:
GET http://climatech.ps/.well-known/acme-challenge/somtestfile HTTP/1.1
Host: climatech.ps
User-Agent: "Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)"
Referer:
Connection: Close
Response Header:
500 read timeout
Content-Type: text/plain
Content (Length = 76):
read·timeout·at·/home/rexswa5/perl5/lib/perl5/Net/HTTP/Methods.pm·line·266.(LF)
Done
Total elapsed time: 5 seconds
with the default User-Agent this:
Rex Swain's HTTP Viewer
http://www.rexswain.com/httpview.html
Code last updated 5 August 2023
Request:
GET http://climatech.ps/.well-known/acme-challenge/somtestfile HTTP/1.1
Host: climatech.ps
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36
Referer: https://www.rexswain.com/httpview.html
Connection: Close
Response Header:
HTTP/1.1 404 Not Found
Cache-Control: private
Date: Sun, 26 Nov 2023 23:49:17 GMT
Server: Microsoft-IIS/10.0
Content-Length: 3208
Content-Type: text/html; charset=utf-8
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
X-Powered-By-Plesk: PleskWin
Content (Length = 3208):
<!DOCTYPE·html>(CR)(LF)
<html>(CR)(LF)
····<head>(CR)(LF)