Sounds ‘normal’ for a lot of people I know :0(, and they are too exhausted to fix things!
However worth keeping an eye it any clues eg wind as others have mentioned, itching / scratching, possible allergy type things; irritation from detergents etc;
Are they hungry, do they look tired but cannot sleep?
Are they on formula, some swear by a bottle before bed as a top up.
‘Good’ sleepers will generally be in a routine so if all else is normal and nothing medically untoward, is there any way you can force the routine. Eg nice wind-down before bed (bath, relaxing stories etx), and lie near them for reassurance.
Gradually wean them of the dependence on you..
Failing that yours might just have a broken sleep sensor :(, return to store for a replacement!