Yes, this is normal behavior for most airliners (low wing and tail)
The technical explanation is;
During initial rotation, the elevator/stabilizer will move closer to ground (tail going down). Here there is very turbulent air from the wing downwash. This means that the elevator no longer will be as efficient and you need to apply more elevator to continue rotation
A few feet after liftoff, the wing will leave Chord Dominated Ground effect, lift will decrease slightly, and the nose might have a tendency to drop unless you continue to increase AoA.
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