<human>: Can you give me the gist of the text in a nutshell?

I have a one year old male labrador that is crate trained. He has no issues going into his crate in the morning when my SO and I go to work. He has a blanket and a kong with him and it is the appropriate size. We even pay for a dog walker to take him out at lunch so he is never in his crate for more than six hours. When the dog walker arrives there are no issues with him howling/barking. In the evening sometimes after he has been in his kennel for only a few hours he will start howling non-stop. There is no discernible pattern to why he starts howling/barking other than it's evening but it's not every night. We tried a vibrating bark collar and I even started going into work earlier so I can get home earlier because the neighbors complained. We have also tried playing NPR while we are away. Today we went to a movie so we were only gone for a few hours and when we got home there was a note on our door that he had started howling again. He gets plenty of exercise and before going to the movie today we took him to the beach and he ran for an hour so he was plenty tired. We have another older dog that is allowed to roam the house I'm not sure if she ever barks while we are gone but I've never received a complaint. I'm not sure what else to do and we are afraid we are going to get kicked out of our condo if we can't address it quickly. Thanks for any advice.
<bot>: One year old lab, crate trained, sometime begins howling after a few hours in evening. Neighbors complained, afraid we are going to get kicked out. Please help!