It is probably a character encoding problem. QuickBase currently uses windows-1552 encoding while most web sites use urf-8.
Wait a minute - I just checked on IE11 and the console is now reporting
On Monday at Empower I checked and Chrome was reporting windows-1552 and I was seeing problem with the question mark in black diamond and non-breaking spaces.
So maybe the QB has fixed this since you asked the question or something else is in the works.
If character problems persist I would suggest you test in several browsers and report the results of typing document.characterSet into the console (press F12 to expose)
Only QuickBase can fix this problem.