same values in google web vitals across transactions

currently we are testing client side metrics using Jmeter selenium framework. Since this framework only provides response time metrics, we are migrating to sitespeed to gather more client side metrics like FCP, LCP,CLS,TTFB, page size.

Application tested- Salesforce (It is not a SPA application . The URL changes for each transaction)
Sitespeed tool version used - 34.12.1 browser time 22.10.2 coach 8.0.2
Browser used - chrome 129

How to reproduce
Execute a user journey (from launch to logout scripted using javascript) and run it locally (not using docker) using the following command.
node sitespeed.js --script.mjs --multi --browsertime.iterations 1 --spa

Issue
For ex, if there are 5 transactions in a user journey. Except the launch transaction, all other transactions shows the same values for google web vitals (TTFB,FCP,LCP,CLS) . But the values for page metrics , CPU metrics, waterfall HAR, Coach score varies.

Transaction Name Total page transfer size Request Fully Loaded TTFB FCP LCP
Launch 7 10 9.25 1.78 1.96 5.23
Login 7.6 226 21.49 2.37 2.52 9.69
Search 39.2 5 2.218 2.37 2.52 9.69
Edit 18.3 7 834ms 2.37 2.52 9.69

Start with the JavaScript user journey in script.mjs and the sitespeed.js entry point, then reproduce the command with --multi, --browsertime.iterations 1, and --spa. Compare how Google Web Vitals are collected for each transaction versus page, CPU, HAR, and Coach metrics; done means per-transaction TTFB, FCP, LCP, and CLS no longer repeat incorrectly.