From my previous and most recent experience google page speed insights is very particular about what it wants you to do and how you should do it - even after making the recommended changes it was unable to use them in there calculations - but with GTMETRIX they appeared immediately and improved pagespeed score from B to A 95% one example is webp image - which we added but for some reason not recognised in Google Pagespeed insights test
Should also mention that one problem i encountered with google page speed insights is that the software you use on your site to say for exampe bundle js needs to be done with the one they suggest