yes, can reproduce not only in Your scene. Thanks.
simpler short time "fix"- render it with production renderer, then start IPR again.
Also refreshing seems to work in our (simpler scene) tests.
In Your scene also- I could reproduce few times, but today, it refreshes with refresh button.
IPR has many other problems. With IPR- feel free to experiment, but don't be surprised when it breaks.
As there is a saying: "Your mileage may vary".