That also happens to me. Yesterday, there is a person who sends me in btc wallet (the one who guided me in this forum). It was so long before I've received his transaction. Almost a day, there is no money in my wallet. Fortunately, he used a link to confirm our transaction. I remember it is viabtc. Finally, I received the money and now I gave it to my mother.
I think the number of transactions result to a slower process. The transaction fee also becomes high because the btc price goes up.