Every generation of processors has a different Microcode version, even when released in the same package.
J6413 belongs to the Elkhart Lake (0x00000017) (microcode-20221108 release
N6005 is in the Jasper Lake (Latest Microcode 0x24000024) (microcode-20230214 Release
The issues that you are facing is not related to the ones in this topic.
For your random reboots, is it on the Proxmox Host or the Proxmox VM?
For the Jasper Lake systems it is the VM, the host is stable and does not have issues.
Usually, we don't recommend Processor Microcode updating as a requirement, unless there is a known errata, or security issue in the processor generation.