Thanks for the report! I've been trying to replicate this Beryllium hang on my end for the last few hours but haven't had 'luck' breaking it yet.
Could you help me investigate? If you can, please join r/atomictest so we can do a proper follow-up. I'd love to know:
Which browser are you using?
Did it happen exactly at the moment of impact or after some time?
If you open the developer console (F12), do you see any red error messages?
I want to kill this bug before moving to the next features.