I recently updated some Terms in the Term Store but they do not get updated correctly on certain sites.
For example I renamed term A to B. On a particular site, I still get A displayed in a list but when I want to edit the item, I see the correct name B. After saving the old name A gets displayed in the list again.
I have waited about a week for everything to sync up but it seems to be some kind of caching issue. I am using SharePoint 2019 on prem and pull the terms every night from SPO. On other sites it seems to work flawlessly.
I also tried updating the terms on this particular site using PowerShell like this:
$tax = Get-SPTaxonomySession -Site mywebapp $ts = $tax.TermStores $site = Get-Spsite https://my.site/with/bad/terms $ts.UpdateUsedTermsOnSite($site