GTmetrix and PageSpeed indicate my files don't get compressed

I've been working on performance profiling recently. PageSpeed suggests enabling text compression, in the Waterfall of GTmetrix, the file is also in uncompressed size. However, when I check the resource from Chrome DevTool, it's well compressed. (size is as expected and the response headers contain gzip settings) On the other hand, running on WebPageTest is perfectly okay.

Don't know if anyone encountered this situation before, thanks