cpu...panic...[kext.kalloc.2048]: element modified after free.... 2021 16'' Big Sur 11.5.1, still happens every day when I start my work in the morning and connect 2 monitors via TB3. Jeeezzzz...

And yes my crash starts with "[kext.kalloc.2048]: element modified after free" and cpu panic as well.

Happens to me as well as described by @dbdotconf. I use 2 monitors with 16'' 2021 Big Sur 11.5.1. The same flow of actions, almost every day when I plug in monitors via 2 TB3, I hear fans and then it crashes and reboots. Also send report every time. This is very annoying. Such amount of money was paid not for such an experience with Mac which is supposed to be ideal.