Those are not "normal" amps but a computer with a power amp and speakers.
The latter can usually be fixed, but the computer part, is only understood by Line 6.
What you have is clearly a Logic problem.
I would write them explaining the problem, *maybe* they can suggest something which you can do, such as replacing some internal lithium button battery or resetting it pushing some special combination of buttons, not much else.
I guess it´s way out of warranty by now.
Worst case, use it in one clean setting like a conventional amp and add pedals at will.
PS: I hope you paid REAL cheap for it, remember in any moment it can even stop making *any* sound at all, forever.
If possible, I would send it back and recover the money.
You will neve be able to play relaxed with it, it can give up at the worst possible moment, such as in the middle of an important show.
Now, if you paid, say, U$50 for it, basically for the speakers and cabinet .... worst case you hook any head to them and forget its electronics.
Even in that case, I would prefer to buy a used cheap 50/80 Peavey (Bandit?), Fender, Laney or Crate which are good and trouble less.
Worst case. *can* be repaired.