Why did the black market value of Iran Rial went upward right after the Iran war starts?

I was just getting myself updated in the Iran rial exchange rates, which had heated discussion when their protests started a few months ago.

I searched "iran rial black market rate" and checked from this website:
https://www.bonbast.com/

It dropped to 1700000+ rial/1usd right before the war, rose to 1500000- right after the war, and drops again recent days.

I thought its value would drop as the oil exports was cut and the regime looks shakier than ever at that time.

Anyone knowledgeable enough to shed light on this? I wonder what kind of funky trade effects is behind this. Thanks.