My company manages several ecommerce sites.

1 of them has this PSI scenario on desktop/origin Field data

PSI Field data

Largest Contentful Paint (LCP)
2.2 s

Page Loads
Good (≤ 2.5 s)
80%
Needs Improvement (2.5 s – 4 s)
12%
Poor (> 4 s)
9%
75th Percentile – 2.2 s
Core Web Vital
Interaction to Next Paint (INP)
321 ms

INP

Page Loads
Good (≤ 200 ms)
61%
Needs Improvement (200 ms – 500 ms)
23%
Poor (> 500 ms)
15%
75th Percentile – 321 ms
Core Web Vital
Cumulative Layout Shift (CLS)
0.19

CLS

Page Loads
Good (≤ 0.1)
62%
Needs Improvement (0.1 – 0.25)
18%
Poor (> 0.25)
19%
75th Percentile – 0.19

For the same site, which has around 7k pages, GSC highlights only 18 pages

GSC Field data

We are struggling undertsanding how this differnce is possible.

NOTE: Validations are not started. Is it something related to it?

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We checked a lot of official doumentation but this point still not clear for us.

Could someone clarify this point pls?

We expect to have a reasonable algnment between GSC and PSI