There are good reasons to doubt the ISIS-K story. From Andrew Korybko at korybko.substack.com:

The GUR learned everything about terrorism from the CIA, but since it’s still a knockoff, it made a series of sloppy mistakes that resulted in incriminating Ukraine instead of lending false credence to the ISIS-K narrative.
Speculation has swirled since Friday night’s terrorist attack at the Crocus City Hall venue in Moscow over whether ISIS-K was really responsible like the group claimed or if Ukraine’s military-intelligence service GUR orchestrated everything under the cover of its agents posing as members of that group. The Mainstream Media is running with the first scenario while doing their utmost to discredit the second, but recalling the GUR’s terrorist history and ties with radical Islamists shows that it’s not above suspicion.
They were responsible for assassinating Darya Dugina in summer 2022, carrying out the Crimean Bridge truck bomb attack that fall, assassinating Vladlen Tatarsky in spring 2023, and the cross–border terrorist raids by the so-called “Russian Volunteer Corps” over the past year. They’re also tied to Crimean Tatar terrorists and ISIS-linked Chechen ones. The CIA is connected with these terrorist acts and groups too after the Washington Post reported last fall that they rebuilt the GUR from the ground-up after 2014.
The modern-day GUR is a product of the CIA, which certainly shared with its protégés everything that it learned while waging the ongoing Hybrid War on Syria, not to mention their terrorist contacts as well. It was through this meticulous cultivation that GUR chief Kirill Budanov obtained his bloodlust that was on full display last spring when he declared that “we’ve been killing Russians and we will keep killing Russians anywhere on the face of this world until the complete victory of Ukraine.”
If it is indiscriminate with collateral damage it is GAE.
If only one target is eliminated then it isn’t.
Isn’t this month Ramadan?
Found out that they wanted to go on March 7 but the security was more intense.
Remember the Eagles Of Death Metal attack?
The singer/guitarist is the legendary Josh Homme of desert rock originator lords Kyuss, he is pro gun, pro Trump and the album insert shows him in jester outfit with AR-15 and a skull as the table centerpiece.
It looks like he is in deep conversation of heavy topics with band mate in the photo. (s/)
These mafias that run the world love to send messages or let people know to stop with what is wrongthink according to them.