While this isnt a Sharepoint error as such, I have seen it appear multiple times in when loading a Sharepoint home page.

When looking online for the error message, I wasnt able to find alot of information as its not a Sharepoint specific error, but more to do with the web browser being used.

After logging this with Microsoft, they pointed me towards this being a browser error message rather than a Sharepoint error message.

It looks to be an issue when only using the old Edge browser as this is only web browser where I am able to replicate, when opening up the same page in a different web browser the error doesnt follow.