Permanent spinning wheel top Right hand corner

[eeeee]

I tried accessing my nodeBB forum from a linux laptop via firefox
It has the blue wheel permanently spinning, it never stops after I made a post.
This never happened with other computers I used.
And it doesn't happen on this instance of nodebb when I am writing this now from the linux laptop.
Any idea what might be causing it?

[eeeee]

Update. I think it might be because there was a gif on the page!