Filing as 10.11v1- critical as previously discussed, to make it show up on the list for consideration. Please feel free to downgrade or close as "won't fix".

For a table with visible versioning columns, setting system_versioning_insert_history variable changes the behavior of inserting default values (restricts it).

create or replace table t (a int auto_increment primary key, s timestamp(6) as row start, e timestamp(6) as row end, period for system_time (s,e)) with system versioning;

set system_versioning_insert_history=off;

insert into t () values (),();

insert into t (a) values (3),(4);

set system_versioning_insert_history=on;

insert into t (a) values (5),(6);

insert into t () values (),();

Both INSERTs with system_versioning_insert_history=off work, with a values inserted according to the auto-increment or explicit values, s to the current time, and e to the max timestamp.
The third INSERT, first with system_versioning_insert_history=on also works, the same way.
But the last INSERT fails:

query 'insert into t () values (),()' failed: ER_WRONG_VALUE (1525): Incorrect s value: '0000-00-00 00:00:00.000000'

There seems to be no good reason for this.