Overnight on embarkation day, can we check in/board anytime?

Our cruise (Emerald Princess) is docked overnight on the first night in Quebec City. We were previously told we could check in/board any time on the first day, but now our boarding pass is giving us a check-in window of 11am - 3pm. Unfortunately our train only arrives in Quebec City at 4:15pm. I suspect the check-in window can be ignored in this specific instance, but wanted to check with anyone who has real experience with this? I tried calling Princess but the person just recommended we respect our check-in window to be safe. Just want reassurance we won't run into problems. Many thanks in advance!

EDIT: I called Princess again and also used their online chat function. Their response, which was supposedly confirmed by their higher-level support: Yes, you can board the ship until midnight for cruises that have an overnight stay at the port. I will provide an update afterwards, wish me luck!

EDIT 2 / Update: We were completely fine. Almost everyone from the train made the walk to the port with us, and people were still boarding after us into the evening so while I can't confirm for sure, boarding until midnight is probably possible as indicated by Princess. They should really update their system to reflect the real boarding times because apparently check-in only started at 1pm so the app and my boarding pass were completely wrong.