GZip for transferable resources

I’ve used this tool many times but never received a result like this before:
“Use gzip compression for transferring compressable responses”.

Can anyone help by explaining this to me? I do have gzip enabled, and, it does not appear on the “unthrottled” results; this appears on a iPhone 8 iOS 12 - LTE testing run (pic attached).

There is a very lengthy htaccess file placed by FastComet support, my server supplier, but that has been in place for a year without seeing this warning.

Information and advice will be appreciated.

Looking at the URL, it looks like the lack of compression is probably by-design. The “speedtest” in the name means it is probably downloading a fixed-size 100KB object to measure the transfer time to figure out the connection bandwidth. From the looks of it, it is probably something like all-zeros or something and compresses down to nothing.

It’s probably going to bug you but if you can, just ignore it and understand that it is intentional and expected for that specific resource.

If you can share a link to a test result I can see if there is anything about the request that makes sense for WPT to use to ignore it when looking for compression but my initial guess would be that there isn’t.