permalinks not functioning properly after migration of cornerstone

I have a website in X theme Icon using cornerstone. Permalinks were set as post name.
Now that the site has been moved to its proper URL , but now the pages only work with pageID and not with page name.
This looks very unprofessional.

The migration has taken place as instructed in: //
I have not done the migration as I am not capable. The IT people who did the migration could not solve this problem.

Site was moved from to
Please help me resolve this.

Hello there,

If you drop me an email with your login credentials, I could just take a look at and offer a price to fix the problem, if you’re interested in.