Symmetrize suddenly started giving unexpected results

Need some help with this sculpt.

As far as I know, I haven’t rotated or transformed this sculpt in any way and I have already symmetrized it quite a few times without any issues but for some reason it suddenly started acting weird. Can anyone please help me? I haven’t made any progress since this issue cropped up. Here’s the post-symmetrize result.

The first screenshot shows unapplied rotation and scale, and the scale is also non-uniform

Thank you so much! Applying scale and rotation fixed the problem.