256 batching limit in URP?

We've recently started using URP and have come across a 256 batching limit when using Sprite Renderers. This limit was not present in our previous project that was not using URP.

Here is the setup to test this:

1. Create a prefab with a Sprite Renderer, a Default Sprite material, and a Sprite.

2. Now duplicate them till you have 256 of them. The 257th duplicate will break batching.

3. Do the same in a non-URP project, and you can go far beyond 256 duplicates without breaking batching.

I understand that dynamic batching has a 900 vertex attribute limit, but if so, why does the 257th duplicate not break batching in a non-URP project(even when using the same material)?

Does anyone have any insight on this?