Potty Training puppy

We adopted a pup from the pound about 5 months ago and we’ve had the most difficult time potty training her. We are at a loss and don’t know where to go from here. She has weeks where she does great and has no accidents. Her accidents are always random. We took her out tonight around 11 pm and by midnight she peed on our bed which absolutely shocked us. She peed outside and can absolutely hold it (she is in the kennel while we work for about 7 hours a day) She has her occasional accidents on our carpet but tonight we are truly stunned. We have another dog that is 5 and she has no accidents. We take her out when we’re home about every 2-3 hours. When she does have her accidents she dosent understand she’s doing anything wrong as she will do it in front of us and cuddle up to us immediately after. We put her in the kennel after her accidents so I truly do not know what to do. Our floors are wet from shampooing from an accident she had last night and our bed is wet from her accident tonight. Please drop tips and tricks!!