Hi @TYCHE and @toupan!
We are extremely interested in these kinds of scenes with flickering caustics. Could you please send us an example scene like this? It can be a production scene, or if you are not allowed to share it, or just don't want to, you can try preproducing the same issue in a simpler scene, or remove some parts of your scene while keeping the issue visible. This would be highly appreciated!
We should also be able to provide you with a workaround, which worked in similar cases, but to verify this, we first need a scene where this can be replicated.
You can use the uploader in my signature and after the successful upload, let me know what was your file name.
Thank you in advance.