Doesn't send proper headers

This issue has been resolved in version 1.1

@markman641 We have resolved the issue you mentioned in our 1.1 version and now released version 2.0 with lot of improvements. We appreciate your review.

Still sends 200 OK header..

Hello @markman641

Strange, we have tried many methods to check the header status and always we are getting 503 header when plugin status is enabled.

Take a look at this link

Please let us know the method you checking to identify the header.

We have tried checking header status on the following tools.

https://tools.seobook.com/server-header-checker/
https://www.internetmarketingninjas.com/header-checker/
https://web-sniffer.net/
https://www.webconfs.com/http-header-check.php

Always we getting 503 header.

HTTP/1.1 503 Service Unavailable =>
Date => Tue, 05 Jan 2016 20:19:11 GMT
Server => Apache/2.2.29 (Unix) mod_ssl/2.2.29 OpenSSL/0.9.8e-fips-rhel5 mod_bwlimited/1.4
X-Powered-By => PHP/5.3.29
Retry-After => Mon, 8 Dec 1969 00:00:00 America/Chicago
Vary => User-Agent,Accept-Encoding
Connection => close
Content-Type => text/html; charset=UTF-8

so please let us know, how you checked,make sure your plugin is up-to-date.

I have seen you suggested to check on web sniffer on another under construction plugin support forum. Here is the result we are getting from web sniffer upon checking an under construction page url.
https://www.acurax.com/construction-maintenance-mode-acurax-demo.php?acx_csma_preview=1

HTTP Request Header

Connect to 209.140.16.91 on port 80 … ok

GET /construction-maintenance-mode-acurax-demo.php?acx_csma_preview=0 HTTP/1.1[CRLF]
Host: https://www.acurax.com [CRLF]
Connection: close[CRLF]
User-Agent: Web-sniffer/1.1.0 (+https://web-sniffer.net/)[CRLF]
Accept-Encoding: gzip[CRLF]
Accept-Charset: ISO-8859-1,UTF-8;q=0.7,*;q=0.7[CRLF]
Cache-Control: no-cache[CRLF]
Accept-Language: de,en;q=0.7,en-us;q=0.3[CRLF]
Referer: https://web-sniffer.net/ [CRLF]
[CRLF]

HTTP Response Header
Name Value Delim
Status: HTTP/1.1 503 Service Unavailable

@markman641 Can we get a response?