Trainers, the Adventure Sync rewards have been extended for one more week, until June 17, 2019, as now confirmed by Niantic Support on their official Twitter account.
The Adventure Sync rewards have been announced for the Adventure Week event, which is now live, but players have issues when activating the Adventure Sync and are not able to receive the rewards.
Pokemon Go’s Adventure Week event started on June 4 and will end on June 11, featuring new cool bonuses, new shiny Pokemon, new Field Research tasks and rewards, rewards when connecting with Adventure Sync and walking 50KM to earn 50,000 Stardust and 15 Rare Candies and other cool bonuses.
The Adventure Sync issue was reported to Niantic by many players and Niantic acknowledged their mistake and they are now extending the Adventure Sync rewards for one more week until June 17 at 9:00 AM.
Trainers, in light of the ongoing Adventure Sync issues, the additional rewards for walking 50km have been extended another week, until June 17th, 9AM. Earn 50,000 Stardust and 15 Rare Candies by walking 50km each week, for both this week and the next!
— Niantic Support (@NianticHelp) June 6, 2019
They also mentioned checking if the Adventure Sync is on in setting, as it might have turned off with the app update which is currently rolling out.