Issues moving domain

Hi all,

Sorry if this is the wrong place to post this, feel free to move it if it is.

We are branching a site that used to be part of a multisite setup to it's own dedicated domain and server. I have everything up and running and the domain is changed in almost every location (the settings) but when users try to access a "Discussions" page it sends them back to the old website (the old domain). I thought this might be an issues with individual nodes already in the db but I am apparently not clear on how to make sure. Is there something simple I am missing or is this a more detailed process and how might I go about it?

Worth noting that even though I inherited this site 1 year ago there are still things here and there that make literally no sense to me, the spaghetti never ends :>

Thanks in advance and I am happy to answer any questions you might have!

Jacob