What OS are you using and how much RAM do you have?
Sounds to me like you have 2 issues; back button and little blue circle (loading icon).
As for the loading icon, this could be a product of the computer hardware and/or your add-ons; not enough RAM and/or too many add-ons, slowing down the browser, not configured correctly.
In my experience, the back button (as well as other keyboard/mouse functions) tend not to work when:
1. Batteries going out on wireless keyboard/mouse.
2. When using an aftermarket wireless keyboard/mouse. Meaning if your PC came with wireless keyboard/mouse and you replaced them with some other brand. An example, it's best to use a Dell keyboard/mouse with a Dell PC. If the PC came with a hardwire (USB or PS2 connector) keyboard/mouse it is best to stay with that configuration.
As for the loading icon, you get this blue circle because it's taking a long time to load the script on the page you're trying to view.
If you are running a number of add-ons and they are not configured correctly, this will hang up a page from loading.
If you are using multiple adblockers, script managers, flash controls, and pop-up blocker it takes getting use to them (configuring) before you achieve the desired effect.
Do you get this loading icon on other sites or just BF?
I can't speak to how this effects BF. If they have a lot of scripts/ads with banners or pictures, I don't seem 'em.
If you're getting this loading icon regularly, on all pages, you might also want to check you system configuration. For W10, hit your Windows key, scroll down to Run, select Windows System, select run, type msconfig, hit OK. When the system configuration window opens you can check to see what's running on your computer; start up and services. You may just have too much stuff running in the back ground eating up your RAM.
Sorry to hear you're still dealing with this.
Good Luck My Friend.