GA4 truncates page names to a maximum length of 300 characters. In this article: the details, how to measure the problem, and a workaround.
What is a session? And how can I use SQL to express that.
This is a guide on how to track Navigation Timing data of all your pages using the Google Stack: Google Tag Manager, Google Analytics (App + Web), Big Query, and Data Studio.
You will get unsampled page-level data of almost all Navigation Timing API requests in a nice and easy to query table.
A quick guide on visualising Snowplow Analytics data (in this case: performance timing) in Google Data Studio.