Hi There, new to this forum, but my Husband and I are in need of desperate help. We have had two female Border Terriers both lovely and super self sufficient amazing healthy and confident dogs. our current female border is nearly two years old. In November we made the decision to add a male border terrier (half sibling) to the female we currently have to the mix. Due to covid, we certainly admit we have some missteps on our end here. Mylo is a great little guy, now 6 months old, very smart, well mannered on leash and leash obedience is great. However, from the get go, we have never truly been able to leave him alone without an issue. the first time we had a big issue was back in December (after having him for 3-4 weeks) we had been putting him in a pen during most of the day but he would come out and play and be with us much more than he would if we had been going to the office. In December we attempted to leave Mylo and sister Millie at home to go to a friends house, the was the first instance of hours on hours of high pitched whining/screaming/yowling drama as he was in a pen and Millie was out. In turn, Millie started to get upset about the ruckus. From there we had tried and tried again to get him used to being left along, we have only had success when we put millie in the exact pen with him. We need to get him to a place where he is comfortable having alone time and not making these crazy sounds, sometimes it's a low whine, other times it sounds like an animal is dying it is so dramatic and haven't been able to get to a point where he stops the noise. we have tried to outlast him and ignore him for at least 8-10 hours to no avail. he is also pretty calm while doing it sitting there in his pen not interacting with his toys because he's too busy throwing his tantrum. we have gotten the advice because in our current situation we can't keep allowing this level of noise to go to a house where noise is not an issue, stick him in a room in his pen with food/water and only let him out for potty breaks until he gets over this. has anyone experienced anything like this? do you feel this approach will work? we are desperate to keep this little guy, but unless we can solve what is going on right now we may have to make a decision we don't want to. any help appreciated.