Confused between lighthouse and WPT

[Cymru]

Hello All,

I've been working hard on my website and I am getting different results. On the lighthouse plugin with Chrome Browser, I get zero CLS but on the WPT report I am showing a CLS of 0.76. The test was run using Dulles, VA - Chrome - Emulated Nexus 5 - 3GFast - Mobile. Any ideas why I get this difference between the two?

Here is my WPT and lighthouse metrics are attached; https://webpagetest.org/result/200722_5V...94bf8f89a/

Thanks in advance.

[pmeenan]

Looks like it is timing sensitive on when different bits rendered but I captured it with the raw video off of the device: https://www.webpagetest.org/getfile.php?..._video.mp4

The phone number at the top shifts slightly when the phone icon next to it renders (6 seconds into the video)

[Cymru]

Cheers Patrick. Really appreciate that mate. I think that is the icon that pushes the phone number around. Will get that sorted. Thank you. I guess I really dont understand why lighthouse on the browser doesn't see that.

[Cymru]

Well this is very confusing. I think we fixed the telephone number bit but I still get different scores at different times. I don't know at this point whether to just give up and say I am happy or keep on chasing.

https://webpagetest.org/result/200723_AX...1c6a90e41/
https://webpagetest.org/result/200723_FW...f81ca3a52/

I guess it could just be a timing issue on the rendering. That's the only thing that makes sense.