Hi everyone,
Just wanted to share a quick tip in case anyone else runs into this problem:
I noticed my Meteor app was running much slower on some Windows machines compared to others. In the browser’s network tab, I saw lots of repeated xhr?t= requests instead of a single stable websocket connection. On my Mac and some other PCs, everything worked fine.
After a lot of digging, I found out the culprit was my antivirus (G Data Internet Security) and specifically its Webfilter feature. When enabled, it was interfering with websocket connections, causing Meteor to fall back to inefficient XHR polling. This made the app much slower and more resource-intensive.
Solution:
Add an exception for your Meteor server (or internal app URL) to the web filtering/exclusion list in your antivirus settings. After doing that, everything worked perfectly—no more XHR floods, and performance went back to normal.
Hope this saves someone else some time and head-scratching!