(Feel free to update this bug's summary to be more specific.)
Component Readiness has found a potential regression in the following test:

[sig-cluster-lifecycle][Feature:Machines][Serial] Managed cluster should grow and decrease when scaling different machineSets simultaneously [Timeout:30m][apigroup:machine.openshift.io] [Suite:openshift/conformance/serial]

Significant regression detected.
Fishers Exact probability of a regression: 99.93%.
Test pass rate dropped from 97.70% to 87.50%.

Sample (being evaluated) Release: 4.20
Start Time: 2025-06-26T00:00:00Z
End Time: 2025-07-03T12:00:00Z
Success Rate: 87.50%
Successes: 21
Failures: 3
Flakes: 0

Base (historical) Release: 4.18
Start Time: 2025-01-26T00:00:00Z
End Time: 2025-02-25T00:00:00Z
Success Rate: 97.70%
Successes: 85
Failures: 2
Flakes: 0

View the test details report for additional context.

This test appears to fail enough (albeit relatively rarely) on vsphere to trip component readiness. Over the last week we're at about 5% fail rate. Prior week was about 23% fail rate.