I was told by the IRS the reason my return was not processed yet is because they need to send me a 5071 c, should I be worried?

https://www.irs.gov/individuals/understanding-your-5071c-letter

The IRS needs to verify your identity. Follow the instructions in the letter when you receive it.

See below for reference.

https://www.thebalance.com/irs-form-5071c-1947701

https://www.irs.gov/individuals/understanding-your-5071c-letter