Its just a mini, but Maybe its because Im using nano pool, they just added support for the Z9 so maybe theres less people over there. Not sure, but you may want to try them out. I have use them for ETH and XMR for quite a while and been very happy with them.
Even so, a different pool surely would not give you that much of a difference, that's like 7 times the shares i am getting?? Just WOW! How much you earning a day? (USD)