A Season Pass is a temporary event with quests that are often updated. This is why you may not be able to pick up the reward for a quest or level pass in time, but don't worry, you won't lose anything!

Hadn't claimed the reward before the quest was updated

The opportunity to claim the reward will also be available after the quest is updated. The new quest will appear after you collect the points.

With the season ending, I didn't have the time to claim points for the quest

If you have not claimed your points for completing a quest before the end of the season, they will automatically be credited to your balance when you log in next time. If the points level up your pass in the meantime, you will be offered a reward.

The season is over, but I haven't claimed the Season Pass level award

If you haven't claimed the reward for your season pass level by the end of the season, you'll be prompted to do so the next time you log in to the game.