Penalty Decisions - Someone Please Explain

Ok I am hoping someone can explain these two decisions because they have me baffled. These two are from the past hour.

https://youtu.be/zBZsMe0faxY A penalty and a yellow card, my defender has the ball and their attacker crashes in behind him.

https://youtu.be/dfTp3DVvZNU My defender receives a yellow card and concedes a penalty for their attacker attempting a bicycle kick and failing. As you can see, while the attempt at a bicycle kick is being made, my defender is just standing there, not even attempting to try and get the ball