My question involves police conduct in the State of: Oregon. Columbia County

I called the deputy sheriff in my county to do a welfare check in my 2 and three yr old sons. After their mother didn't show up to drop them off. It is court ordered. The deputybjas been very involved with listening to my ex and all of her lies about me. Law enforcement and DHS are all very aware of my ex's abuse and suicide attempt history. So when she didn't show up or call to drop them off according to the court order, I called non emergency disbatch to do a welfare check because I knew something wasn't right. The deputy told me no. He said he talked to my ex's "father". Who is actually her boyfriend. And he said the children are safe. I begged him to check on my boys. He repeatedly told me know. After not seeing my boys for 6 days. They randomly gave them back covered in bruises 2 days after I begged the sheriff to do a welfare check! I video taped picking them up. Didn't turn the camera off. Drove down the road. Taped taking pictures of my hous with their clothes off. Took video and pictures of all of the bruises.and marks. Take them directly to the emergency room. Call the child abuse hotline. Call 911 to report the abuse. Take them to dhs the next morning. And child protective services takes them away from me!
I just got them back after 6 days of their mother being in contempt of court. I had them for 15 hours and they take them from me!

My question is: does a sheriff have to do a welfare check when children are.involved and you are the legal parent?