Previously working GPT has stopped after adding instructions in chat (Create not Configure pane)

[white anvil]

Steps to reproduce:

1. Make a GPT, private publish with link
2. Later, come back and add more instructions in the chat interface (left "Create" pane), each with a successful response confirmation
3. Try to ask the previously-working GPT a question

Expected result:
4. Get Answers especially for the new instructions

Actual result:
4. Get error repeatedly, even after closing and reopening (see screenshot)

Additional information
Browser: Chrome
OS: MacOS

[white anvil]

Update: after I replace the new Instructions and Conversation Starters your app added (see my other bug https://discord.com/channels/974519864045756446/1171594168427085834)... it seems to work again.