My 2w-3d old baby wriggles to the edge of her bassinet every night. We've tried her in the arms up love to dream and arms down ergo pouches, as well as a light blanket tucked over her lower body. I have to move her back to the centre at every feed (4hourly). Is there a reason for this? She isn't rolling. Just wriggling her whole body diagonally so her face is almost smushed up against the wall.

Many babies will wriggle & change position (like you describe) at a young age.
While most babies do not roll intentionally till about 3 months, some do roll early.
If she appears to be intentionally rolling, please see the following info:
https://rednose.org.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over

Also, some babies just do not respond well to wrapping & like their arms free.
Often these babies like their arms free or like to touch their face or suck fingers & will wriggle to get free.

You could consider moving her to her cot &/or cease wrapping or wrap only under her arms (ie with arms free as for 3mth old)).
Baby needs arms free & the space of the cot to roll safely.
Red Nose recommends to “modify a wrap” once baby is around 3 mths of age in preparation for rolling (if they are not already rolling)
If baby is rolling (or making an attempt to roll, then wrapping needs to be ceased.
https://rednose.org.au/article/wrapping-babies

Once baby is showing signs of being able to roll, it’s time to move baby to a safe cot – this is usually around four months, but it will depend on your baby.
https://rednose.org.au/article/bassinets