I was quite surprised when I first learned it, there are insurance companies which specialize in selling insurance to insurance companies in case the insurances they sold have to be paid. See Reinsurance on Wikipedia for example.
Obviously Reinsurance companies might reinsure their claims to other Reinsurance companies until nobody knows who is actually paying.
Similar to packing rotting investments with other investments and selling them to retirement founds, because hey look, there are good investments in it.
Maybe I remember it wrong, been a while since I had contact with the insurance industry.
Also might depend on national insurance regulations.
I assume you’re right since you are in the sector, but I don’t know where I picked up the notion, that reinsurers would reinsure themselves.