Ticket Links lost after upgrade RT4.3 to RT5

I just upgraded to RT 5.
Everything looks good.
Some users report slow performance.
Tickets with links seem to have lost the links visibly.
Yet if we look at the page source we see the links.
Any ideas would be appreciated.

Did you by any chance also change domain of your RT installation after upgrading (e.g. from “https://myrt4.com” to “https://myrt5.com”)?

thank you for the suggestion.
No it is the same - I did a diff of the RT_Config and RT_SiteConfig and made sure these options are the same.

Could you explain this a little more. Does this mean that the links are no longer visible at all on a ticket? Or users can see the link but when they click it something goes wrong?

I’ve found the problem.
I had the Organization wrong.
once I fixed it and updated the Links table accordingly all is good.
Sorry for the confusion.