What is the name of the domain?
What is the error number?
No error number
What is the error message?
LCP Score Increases From 1.9 seconds to 7 seconds Within Minutes
What is the issue you’re encountering
Website speed instability with web vital fails on 140 pages and pagespeed scores that go from 1.9 seconds to 7 seconds within minutes of testing on same page
What steps have you taken to resolve the issue?
My website, armorthane.com, typically performs well on PageSpeed tests—usually landing in the 98–99% range with load times around 1–2 seconds. That said, I’ve been running into some performance instability I haven’t been able to trace. At times, I’ll rerun a scan and see LCP scores drop dramatically, with render delays exceeding 90% and load times jumping to 6–8 seconds. To make things worse, over 100 pages are currently failing Core Web Vitals on mobile.
I’ve been using the Seraphinite Solutions cache plugin, which has served me reliably for a couple of years. Their development team reviewed the data and pointed to a potential server-side issue. However, I’m on a high-performance dedicated server, and none of my diagnostic tests suggest a hardware or configuration problem. I also have Cloudflare in place with auto-caching enabled to help smooth out delivery.
Still, the inconsistency remains. I’ve seen scans go from excellent to poor within minutes, with no meaningful changes in traffic or content. That makes me question whether the caching plugin is occasionally failing to serve optimized content—or if something deeper at the code level is contributing to the problem.
Here are two PageSpeed scans of the exact same page, taken about 20 minutes apart:
Poor performance (6-second LCP):
Good performance (1.9-second LCP):
If you’ve run into anything like this—or have ideas for troubleshooting—I’d be grateful for your input. Thanks in advance.
What are the steps to reproduce the issue?
Running pagespeed tests will give me drastically different results within minutes of eachother.
