The reason the resource manager is not working is as follows:
See attach [https://bugs.limesurvey.org/file_download.php?file_id=16597&type=bug&show_inline=1&file_show_inline_token=20221223zw8L2wYBcgB19J5E5_-X6_NZmJdVg0Pn]

The reason why this doesn't work is that if you look at the line marked with x in the image, this value is used to set the cookie in the browser if a subdomain is detected. However, this fails if a port is set since browser cookies don't support ports. For the ip address with port a simple regex could be attached (1 in image)

$ip = '/^' . implode('\.', array($ip, $ip, $ip, $ip)) . '(:\d+)?$/';

The value for the line marked with x in the image could be changed to empty string just as the condition before, but this would make the whole condition irrelevant since you could just always set

$this->config['cookieDomain'] = "";

which sets the current domain as the cookie Domain, which is what we always want or is that a wrong assumption?