@raywoodcock - That is a separate issue with the forums (which is on a different code base) and has been reported.
Using PRE or SPAN tags around your URL (that you want to render as plain text) will work on your site, and this is something I have tested and verified.
There may well be solutions that a dedicated HTML coder could manage. But I'm not that. I'm just trying to write my blogs. I don't know how to do what you're describing, and I dread the thought of trying to manage it within a table or other complex HTML.
There is no other way to prevent automatic linking, so you will need to add HTML tags to get what you are after.
If you are uncomfortable with composing your posts in the Text (HTML) editor, you can write the entire post first in the visual editor. Then switch to the text view, and use the search function in your browser to locate the strings you want to not be converted to links by adding the appropriate HTML.
I don't understand why things were changed.
It is uncommon for users to add a URL to a post and not want it to be a link. So for them, this is a great convenience. With that in mind, it's worth noting that this is a feature, and not a bug, and not something that we'll be "fixing" any time soon.