In this situation, are you required to change lanes?

Why?

Your left-hand lane has a P-9 lane-change arrow pointing right. It requires you to move into the adjacent right-hand lane, so changing lanes is mandatory. The upright sign visible earlier also shows that the left-hand lane ends.

§ 87 ust. 3 rozporządzenia w sprawie znaków i sygnałów drogowych