[Bug Report] Ineffective start_time in Mission

[qianyi-sun]

High Level Description

When creating a mission in scenario.py like the following, the start_time=10 seems ineffective. No matter what value it is, this mission always start at the first step of simulation. Please find attachment for the scenario.
social_lead_traffic.zip

leader_mission = [
    Mission(
        route=Route(
            begin=("E0", 1, 13),
            end=("E0", 0, "max"),
        ),
        via=(
            Via(
                "E0",
                lane_offset=100,
                lane_index=0,
                required_speed=15,
            ),
            Via(
                "E0",
                lane_offset=200,
                lane_index=1,
                required_speed=20,
            ),
            Via(
                "E0",
                lane_offset=250,
                lane_index=0,
                required_speed=7,
            ),
        ),
        start_time=10,
    ),
]

Version

Up to date to the latest master branch

Steps to reproduce the bug

git checkout pat/following_scenarios &&
scl scenario build --clean <scenario_path> &&
scl run --envision <any_example> <scenario_path>

System info

No response

Error logs and screenshots

No response

Impact (If known)

No response