end of the URL bar is flashing constantly and causing immense slowdown
This will happen and cause the page to stall, not load, which is especially bad on a page with a download link or if it's a search engine. The highlighted part of the attached image is an example of which part of the URL flashes incredibly fast - appearing and disappearing.
I just recently had an instance of the url bar typing the same word and deleting it over and over again at the end of the address. I was watching the word "drawers" appear as if I was typing it myself, letter by letter.
Refreshing doesn't help and will refresh the previous page because the faulty link will carry over to the next page if it's on a search engine for example.