Picking up incorrect siteID

We have 6 users that are picking up the incorrect siteID.

https://communities.bentley.com/products/licensing/w/licensing__wiki/7695/activation-of-client-side-products-and-registry-basics

We can correct this within the registry however soon as the application is opened it reverts back to the incorrect SiteID.

Struggling to find further guidance on how this is SiteID is set. Can anyone point me in the right direction, thanks.