EasyBlog Composer Embeddables Blocks - JSON response variable "oembed" always null or empty

Hello and good day,

I will start by saying I know this might be beyond the scope of your support, but this is the ONLY feature that I cannot get working on my locally hosted site and I cannot figure out why. I am hoping that as the developers of this web app, you can point me in the right direction or even supply a fix.

I am having a lot of trouble with the embeddable video blocks in EasyBlog Composer on a locally hosted site. Other embed blocks (such as CodePen) work fine.
When I move the site to a web host, everything works fine! This leads me to believe there are conflicting configurations on the two web servers, but I cannot find the differences.

I have been able to narrow the failure down to the JSON response when clicking "Embed Video". I have attached images of the working and non working information; the screenshots were taken of the POST request when clicking Embed Video on the YouTube block.
When it doesn't work (on a localhost), the oembed variable in the response is null, or sometimes it is Object, but there is no data.
When it does work (web-hosted server), the oembed variable is fully populated.

I tried adding Header set Access-Control-Allow-Origin "*" and Header unset Content-Length to my apache configuration but it did not fix anything. keepAlive is On. There are no entries in the apache error_log.

Do you know of a limitation that prevents locally hosted sites from using the embed blocks?
Or have any ideas to further troubleshoot this?

At the moment, I cannot provide site access. I am working on allowing the server through the firewall to allow your team to troubleshoot this with me, but it is going to take a few days. I am just posting this now in the hopes that you might have some ideas.

Thank you!