Resolution and explanation
When the agent software is stopped abruptly on the protected machine, caused by the BSoD for example, agent detecting that as a "dirty shutdown" and can no longer maintain changed data integrity for incremental snapshots. Thus, the next requested snapshot will initiate a base image backup on all disks.
This behavior is by design.
Note: this behavior is by design and it doesn't matter if machine is protected by agent or agent-less. Unexpected guest VM stop is also may cause changeblock tracking to be reset.