I’m having the same issue.
upgraded to nextjs 15.5.2 and its returning internal server error on the console and snapshot is not a function.
And I have no change that will warrant that error.
however, the app worked well when I downgraded to 14.3.3
I think netlify has an issue with nextjs 15 and above upgrade. please whats the way forward I need to upgrade my next to 15