Perhaps we know, but the reasons will be unpopular.
and the islamic regime was a sponsor of previous pro-palestine movements.
leftists don't find this an appealing mix. they'd rather blame Israel for everything, but here we see Iranians siding with the Israelis because they've seen what islam does to their country.
I think its simpler. There is no one white involved. What is unique about Israel is that most of its population is white so its an issue worth covering (for people backing either side). The same with Ukraine. On the other hand what happens in Eritrea or Sudan or Myanmar or Xinjiang does not matter.
Iran's population is also overwhelmingly pro-West.