We've got a 14 weeks old boy, and he hates being left alone. We've had him since he was 8 weeks and 5 days old. We both work from home, so we are mostly at home, but of course we have to be able to leave him for a couple of hours eventually.
When we first got him, we introduced him to the crate and let him sleep in there (we would put the crate into our bedroom at night, and back into the living area during the day). After like 2 or 3 days he was completely fine with it; he would much prefer his other bed (a cosy cave) though, but he would sleep though the whole night without whining. We since have transitioned to let him sleep in his cosy cave bed at night which we put just outside our open bedroom, he does great there and obviously likes it better (and we do too).
He's still fine with his crate though, goes in on command super promptly, and without command also during the day to snuffle around (never to sleep though).
We're now trying to get him to keep quiet in his crate when we leave the house. We give him a stuffed frozen cow hoof which he absolutely loves. We make sure he doesn't need the bathroom, is not starving but still keen on his hoof, and adequately tired from previous activities. We turn on the tv for him and I've set up a live stream so we can watch how he is doing.
It's the same every time: for the first 20 to 30 minutes he is just glued to his hoof. After that he starts crying and barking. The time span in which he is happily chewing on his treat does not seem to get longer, but there would still be food in it when we come back. We do not make a fuss when we leave or when we come back.
We've been doing that exercise once a day for more than a week now, and it doesn't seem to get better. We actually leave the house and drive off, so he can't hear us around, and we only leave for 20-60 minutes. It's always the same; on the shorter trips we might arrive back before he started whining, but most of the times we don't, and that means we wait quietly in the car port until he's been quiet for at least 30 seconds (and that can take a while.... :/)
It's frustrating though, because it does not seem to improve at all
Also it is quite disrupting, not fun and the time we are gone is not quite long enough to actually get anything done. Are we doing it right? Should we just leave for longer periods and let him exhaust himself? Or will it get better the way we're doing it now?