RMD for Inherited IRA when owner died in previous year

Greetings:  Mom died in December 2023. Prior to her death, she did take her RMD for 2023.  I was named Primary beneficiary of her IRA.  The financial institution did not get around to transferring it to me until February 2024. So as of February 2024 I am the owner of this Inherited IRA.  I have determined I am an "designated beneficiary", so no special circumstances exist.  I am 76 years old.  When I asked the financial institution what my RMD would be for 2024, they stated because it was transferred to me in 2024 (not 2023), the RMD , for 2024 only,  would still be based on Mom's age (95) (as if she were still alive).  I was thinking my 2024 would be based on my age, Single Life Expectancy, 10 yr rule.   Who is correct?   Thanks in advance for your advice.