Post file to https server in Windows fails

I'm having a weird issue. I developed an application with WebAssembly to upload an MP3 file to my php server. Everything works perfectly when using the app with Chromium on a MacBook laptop. 

I setup the web server to use secure connection with Lets Encrypt certificates on a Linux server in the cloud. If I use the app from a Chromium or Firefox browser on a Windows computer, the file upload to my web server fails. I use the exact same code and same url to post the file to. I only get a 400 error from my server. I checked my server logs and the post url is empty!!!! 

I'm able to post API functions perfectly using a windows computer. But I'm unable to post a file to my server with the same windows computer.

Here's a Apache2 log when it works from my MacBook:
208.103.228.95 - - [27/Feb/2022:13:57:34 +0000] "POST /admin/upload.php HTTP/1.1" 200 847 "https://xxxxx.xxxxxx.com/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.109 Safari/537.36"

Here's the Apache2 log when I use a windows computer:
208.103.228.95 - - [27/Feb/2022:14:20:39 +0000] "-" 400 575 "" "-"

I use the exact same wasm code, but it fails to run properly from Windows. I monitor the console logs from Chrome and I only get the 400 server error code. Nothing else.

But if I use the exact same code over the non encrypted http connection, it works perfectly from both Mac and Windows.

I tried running the server with NGINX and I get the same results. I ruled out the problem on the server. I suspect an issue with Windows encryption certificate.

Can anyone tell me what is going on? It seems to be an issue with the browser on Windows being unable to encrypt the SSL body to post to my server.

Thank you.