Anyone any advice how to get payments completed from Antpool ?

I have the following :
2018-05-18 - 26BTM - paid
2018-05-19 - 15BTM - paying
2018-05-20 - 6BTM - paid
2018-05-21 - 21BTM : paying
2018-05-22 - 16BTM : paying
2018-05-23 - 16BTM : paid
2018-05-24 - 18BTM : paying
2018-05-25 - 13BTM : paid
2018-05-26 - 13BTM : paid
2018-05-27 - 7BTM : paid

So it seems very inconsistent and I have concerned those payments are stuck    - any advice ?