I found this on the FDIC website when researching the deposits insurance coverage limits.
Hopefully it can answer the questions you may have about the insurance limitations.
Welcome to the FDIC’s Electronic Deposit Insurance Estimator (EDIE)
https://www5.fdic.gov/edie/
How Are My Deposit Accounts Insured by the FDIC?
https://www.fdic.gov/deposit/covered/categories.html
Deposit Insurance FAQs
https://www.fdic.gov/deposit/deposits/faq.html
Deposit Insurance Brochures (You can download two informative brochures in pdf format)
Deposit Insurance at a Glance & Your Insured Deposits
https://www.fdic.gov/deposit/deposits/brochures.html#your_insured_deposits