Is This Allowed?

Location: Wisconsin

(Background info) About 4 years ago I moved in with my bf. He has a daughter with another woman, they had 50/50 custody at that time. But when his daughter was with her, she had to get physically removed from her home due to physical abuse and neglect. So she was placed with us 100%. CPS has been involved since then. We still live together + a baby between him & I.

His daughter's mother has called welfare checks on us multiple times, for the smallest reasons known to man. (Me posting pictures of their daughter celebrating her birthday, Christmas, holidays, etc) CPS has confirmed it was okay for me to do that since nothing about it was inappropriate. But my bf was out at a bar one night while I was at home with our kids, he had a little too much to drink and was escorted home. No problems, he didnt get into trouble. But one of the mothers friends heard, told her, and she called a welfare check on us the next morning. Our kids grandparents picked them up for church early that morning so they were gone. But CPS and the cops were at our front door telling us we need to go in for drug testing, and we werent allowed to see either of our children until we talked to the social worker. Our kids were still with their grandparents, but the social worker called them and told them that we could not come get our kids, I wasnt allowed to go see my baby. Even though I had nothing to do with what happened, and their father didnt get into any kind of trouble. But they kept our kids from us until we went in and got drug tested. Even though I wasnt even involved, they still kept me from my baby, when there isnt a CPS involvement with him, just my step daughter. Because of her biological mother. I feel that shouldnt have happened, and I should have been allowed to go see my baby. They kept them for almost a full 24 hours. Everything is okay now, but were they allowed to take my baby from me like that?