Middle ground
The middle-ground fallacy is when you assume the right answer must be halfway between two opposing views. Sometimes one side is right and the other wrong—the middle can be wrong too. Compromise can be good for agreement, but truth isn't always in the middle. The fallacy is to treat the average of two positions as correct. When the dispute is about facts or logic, we need evidence and argument, not just splitting the difference.
Examples
She says the earth is round, he says it's flat, so the truth is probably somewhere in between.
One side says 0% tax, the other says 50%—so 25% is right.
They say it works, they say it doesn't—so it probably works a bit.
Half say guilty, half say innocent—so we'll call it a hung jury.
One expert says safe, one says dangerous—so it's somewhat risky.