I had this issue too with my iphone5. I guess it might be caused I tried to copy a link from Google chrome / Safari (a photo link) to my buddies comment in the Facebook app Comment, when this started happening. I think it has something to do with integrating Facebook with other copied links or items. Try this out hopefully this helps because it seems to have stopped for me.
(Please note this was done with an iPhone)
--> Ensure no links/ or odd texts are currently set in your copy hold
--> in notepad type something and copy it (this will hold a non-glitch text?? )
--> log out of Facebook
--> close all browser apps ( Safari / Google chrome)
--> in settings clear history and clear cookies and data
--> close all apps (double tap home and [x] all the open programs)
--> reset/ turn off your phone
--> turn on your phone and open up a browser and try a website.
Hope this clears up the issue. Best of luck.