11w puppy started pooping in his carte

Hi everyone,

I need help, I’m really frustrated.

We started crate training our 11week puppy. We got him at 8 weeks and immediately went into a crate. Breakfast is at 6:30am, dinner at 6pm. We wake up at 6 and go out for potty, then come back have bf & water and that is the last water as we leave for work at 9. Same goes for dinner last water is around 7pm. We go multiple times after eating for potty breaks, and he used to go potty after 15min of eating. No accidents in crate until last week. He had diarrhea for one day last weeks and had a crate accident. After that moment he is pooping in his crate!! I take him out after eating and now he doesn’t go outside as he used to, even though I’m taking him out every 30min. He waits until he is alone in his crate to poop. I don’t know if it’s because it’s cold outside (-30°C) or because he figured out he can poop inside? Please help