Get F12 error when the IIS is setup with :9445 port


Actually, I have been asking your support via email but someone from your team replying that my setup is incorrectly. Therefore, I want to post here to ask, and I think everything can be achievable. (See what's the trade-off) it should be relating some product change.

I'm running SharePoint 2019 On-Premise with Plumail form 1.9.1 and I have an SSL website (internal site) which is like and because I have serval sites need to be serving by 2 web servers only so I have several application ports as one of it like, and user will access and the network load balancer (which also imported with the SSL cert) and forward it to the SharePoint Web server port :9445, and in SharePoint configured with as an Alternative Access Mapping already. The native SharePoint sites and pages can be accessible, but when I open Plumsail forms, and I get "An error has occurred. Please check the browser console (F12)".
Further checked with this is caused by the CORs policy blocked, and I can see the form has been loaded in flash way and this error shown and make the form disappeared.

and i proved to use Chorme to disable web security and it works to show the form and data!

From your support saying because there are 2 domains those name not a same domain that's why and caused this F12 issue and I wonder why other SharePoint pages can be accessible and rendered? Surely your product can't handle with different ports name!

Therefore, please advise how to address\disable CORs setting in Plumsail form designer! I think there can be achievable in the code!

Dear @patrick1,
Welcome to the community! We did have a discussion with our dev team on the matter before, and from what we can see this configuration does not appear to function correctly.

From the console log other services, such as integrated SharePoint search, are also affected:

Unfortunately, it's not something we can technically support. As our dev lead says:

It's incorrect configuration of the web application when the users are accessing forms by one address, but the data is requested by another. Access mapping should be adjusted in Central Administration:
Configure alternate access mappings for SharePoint Server - SharePoint Server | Microsoft Learn

The problem is not the use of a port, but the fact that both addresses are used at the same time.