The baby in the stroller won't sleep anymore ? He used to fall asleep …

The baby in the stroller won't sleep anymore ? He used to fall asleep outside immediately after we went out but now he doesn't. I have to hold him while rocking him until he falls asleep then put him in the stroller and he sleeps for a maximum of an hour outside. We used to go out at least for an hour on the street, even if he slept outside, but at home he only sleeps with me during the day on my chest. We have a jogging stroller, I raise the backrest slightly so he can see lying down but he doesn't want to lie down either, he just wants to look around ? When I lower the backrest to the lying position, it will always be like that or something might change?