Single Member LLC — Do I Actually Need an Operating Agreement?

Looking for advice on this situation. Single Member LLC - Do I Actually Need an Operating Agreement?

Details: I'm in a situation where I need to understand my legal options. Has anyone dealt with something similar?

Update: Thanks everyone for the guidance. I consulted with an attorney and we're moving forward. The advice here helped me understand what questions to ask and what to expect. Will update when there's a resolution....

For anyone doing a Series LLC: be aware that not all states recognize them. If you're operating in a state that doesn't recognize the series structure, you might not get the liability protection you think you have.