AI had 2 Sakura-Tribe Elder,sacrificed 1 Sakura-Tribe Elder while AI was attacking(unblocked still AI wrongly sacrificed it before doing damage) and so tapped (if it makes a difference)but no land entered the battlefield although AI had lots of lands in library and fetch is not optional.In second main phase AI sacrificed his 2nd Sakura-Tribe Elder (this one didn't attack probably) but this time it correctly fetched a land.In screenshot you can see only 1 tapped land that entered tapped instead of 2 just after AI's turn in my upkeep.