Embeding streamlit cloud URL with <iframe>

I’m currently getting an error streamlitapp.com redirected you too many times.”

This is happening with a custom URL with an iframe, and always occurs regardless of whether I use the format https://xyz.streamlitapp.com/?embedded=true or https://xyz.streamlitapp.com or https://share.streamlit.xyz.py

This appears to be linked to this thread here

Update: rebooting the app has appeared to solve the issue