Exponential slowdown with cross-referencing `oneOf`/`anyOf` definitions

Prerequisites

• I have searched the existing issues
• I understand that providing a SSCCE example is tremendously useful to the maintainers.
• I have read the documentation
• Ideally, I'm providing a sample JSFiddle, Codesandbox.io or preferably a shared playground link demonstrating the issue.

What theme are you using?

other

Version

6.4.1

Current Behavior

Schemas where definitions reference each other through oneOf/anyOf become unresponsive at deeper nesting levels. The time to select an option grows exponentially with depth.

Using the attached schema (5 definitions, each with a child property whose oneOf references the other 4), here are the measured times:

Nesting depth	Time to select an option
8	4s
9	13s
10	49s

The time roughly triples with each additional level. With more definitions, the freeze happens at shallower depth.

Expected Behavior

The form should remain responsive regardless of the number of definitions or depth.

Steps To Reproduce

1. Open the playground with this schema (5 definitions, A through E, each referencing the other 4 via oneOf).
2. Start selecting nested options: pick a type for child, then pick a type for that child's child, and so on.
3. Around depth 8-9 the form freezes for a noticeable number of seconds.