7 month old puppy refuses to poop outside.

As stated in the title, I am at a breaking point with my 7 month old labradoodle/border collie puppy. I made a previous post before stating my issues, yet this one still remains. No matter what I do or have done he won’t do it, ONE time he has pooped outside out of pure desperation. I have had him since he was 9 weeks old. I wake up to smell poop, go to the bathroom and he has snuck away to poop, we go outside at least 7-10times in a day, sometimes only for when he had to pee, 3x for a 30min walk. I have taken his poop outside after pooping inside so he can associate that with pooping outside, I know when he has to poop so I wait outside and wait AND WAIT. But as soon as I go upstairs he lets it rip EVERYWHERE. Up and down my hallway, starts at one end of the house and brings it all the way to the other. I can barely stand it anymore and it’s making me not like or enjoy him anymore. PLEASE if you have any helpful pieces of advice I am more than welcome to taking anything at this point. I live in apartments so a lot of options are limited for me.

Thank you in advance. 😔