

Crate training (and general help)
We’ve had our sweet baby boy for about 4 months - he’s 10 months old - and in general he is great. He plays by himself and is gentle and loving and goofy. His sister is a five-year-old very well-trained Australian cattle mix that puts up with his shenanigans really well, but his good behavior hasn’t seemed to rub off on him.
The main issue my fiancé and I are having is his crate training, or lack thereof. He sleeps in the crate every night by himself and we leave him in there when we leave and he barks every time without fail for 10-30 minutes (or longer sometimes) until stopping and will start up again for a few minutes every couple of hours or so. It’s better when we are at home and just sleeping, but it’s still unbearable. I’m also anxious about my neighbors. If we bring his crate in the bedroom at night there is not a peep, so he clearly wants to be with us (also for context our other dog sleeps with us in our room on her dog bed).
The issue is I’ve been home nearly every day all day since we got him since I graduated law school, but I start work in the fall and he needs to learn to be alone for longer. We continue to try to teach him “go to your crate” and make it a place he wants to be with lock mats etc. But he knows our bullshit and that we are trying to lure him in there and often refuses to listen.
He barks when we leave him alone in his gates pen area - we try to restrict his access in this house if we aren’t going to be taking him out in the next hour or so to help with potty training since he still occasionally has accidents - and he barks at other dogs on walks (we try to redirect with “sit” and “eyes” but it’s hard to get him to focus unless the treat is right in front of his snout). Sometimes we let him engage with smaller dogs on walks, but we want to ensure that first his focus and recall is with us and then he gets permission.
As noted above our other dog is very smart, super well-trained and a really good girl, but we did and still do use negative training (prong collar I know there are mixed opinions about this, but a past trainer suggested it and it is the only thing that really worked), with plenty of positive with treats and toys, but we’ve heard not to use negative training on dachshunds as it’s ineffective (I would obviously never use a prong collar because of their backs) but he just isn’t listening.
What are we doing wrong?