New Growling

Hi, i’m still getting the hang of my Aussie who is now 3 years old. I have had many problems arise with him, he is decently trained but i could train him more but onto the main issue. When I first go him, he was not kennel trained, he is now kennel trained but whenever I would get him a bed in the past he would destroy and eat the stuffing, i switched to a blanket, which he destroyed and ate, finally i was left with just leaving him a towel, which after having for an hour, he destroyed but didn’t eat it (a win). I was left with no choice but to leave him with just the kennel tray for the time being, well i recently got him a new bed and blanket since the winter months have begun to get colder than usual, for context we have heaters pointing towards them so they don’t get cold regardless but it has been getting colder and we are taking extra steps. Since he had gone a while without a bed he didn’t know how to process it, once i put it into his kennel he is loving it but once I get in the kennel to pet him and stuff he starts to growl, mind you he has never done this when it was just the tray so I assume he immediately grew attached to it. How can i continue to pet him in the kennel without growling, i figured its a form of resource guarding but that is a habit of his i have yet to break, anybody have any tips?