9SA5 Accuracy Issues: Root Cause? Fixed?

There are a significant number of posts over the last several years on this and other forums about 9SA5 movements running too fast. Some of these posts suggest that GS warranty service did not provided a long-term solution.

So I'm wondering:

• Has anyone heard from GS what caused this issue?
• Does anyone have a 9SA5 built in 2024 or later that has this issue?
• If you had your 9SA5 fixed under warranty by GS, how accurate is it now?