`cross` plus small grammar causes infinite loop in term generation

[florence]

The program:

#lang racket
(require redex/reduction-semantics)

(define-language esterel-check
  (p ::= nothing (ρ θ p))
  (θ ::= · (S θ)))

(redex-check
 esterel-check
 (cross p)
 (displayln "running")
 #:attempts 100)

Never prints running and eventually consumes all my memory.

This seems to be new behavior since 4bb07c7baa2cb33. I am current on git HEAD.