There is more to this than is being reported. There is an insurgency going on a Jihad being financed by foreign money ie Saudi  Arabia to create an independent state The violence is on both sides. Buddhists don't flee t across the border to Bangladesh but they are fleeing thir villages   It is not so different than other wars going on in ME wth an assortment of world actors who want outcomes rather than the status quo
Here is one account of  the leader of this group.
"It acts under the name Arakan Rohingya Salvation Army (ARSA) and is led by Ataullah abu Ammar Junjuni, a Jihadist from Pakistan. (ARSA earlier operated under the name Harakah al-Yakin, or Faith Movement.) Ataullah was born into the large Rohingya community of Karachi, Pakistan. He grew up and was educated in Saudi Arabia. He received military training in Pakistan and worked as Wahhabi Imam in Saudi Arabia before he came to Myanmar. He has since brainwashed, hired and trained a local guerrilla army of some 1,000 Takfiris."