It's not proven (at least for certain, unless there's more up to date studies I'm unaware of), but many studies do suggest that lack of sleep can slow down weight loss. It's unclear whether it's more direct (ie, actual lack of sleep causes you to lose less weight for whatever reason, hormones etc even if your calories remain the same) or indirect (ie, lack of sleep causes you to eat more/move less, thus lose weight slower).
I think the main studies suggest lack of sleep impacts glucose and insulin levels so you can google how that impacts weight if you wish.
Also, and easier to understand for the average person lol, many studies show that
Lack of sleep = more time awake = more time to eat.
Lack of sleep = tired = less likely to exercise
Lack of sleep = more stressed/less happy = less control over food/increased desire to eat.
You get the idea that there's many factors at play and thus further research needs to be done, however it is generally agreed that lack of sleep does impact weight loss, but it is uncertain exactly how or why, and who and how many people this effects
To assess if your sleep could impact your weight loss, just ask yourself if you wake up feeling refreshed or not. Some people only need 5 or 6 hours, whereas others need 8 or 9 to feel refreshed. Waking up to empty your bladder or to change position doesn't usually impact overall sleep so I wouldn't worry about that. However if you're waking up tired, not feeling refreshed etc then I think you probably need longer in bed