Something clogging the dip tube causing turbulence and foam? I think I'd disconnect the QD first, disassemble and clean and reattach. Or use a different one. If you have multiple faucets, what happens when you switch the line?
Did you dry hop or add something like coffee beans or cocoa nibs or...something like that?
And this is very unlikely, but if you have a hole in your dip tube, or it's not fully sealed somehow (more likely), you may be leaking CO2 into the line along with the beer.
Just some ideas.