Ukrainian problems center on pandemic corruption both government and in private industry. Arcelor Mittal is foreign owned and reasonably well run. They have come under fire from corrupt government appointees who want more bribes..
In fact Zelensky himself was outspoken attacking Arcelor. I have no idea how well founded the government claims of wrongdoing but it is the biggest foreign investor who dared investing $9 billion. Attacking it sends awful signal for others.