Problem with author name (same surname, same year, but different initials) - Endnote uses a,b in references

Hello,

I am having a problem with my citations (in text & references)

I have two citations:

Miller, S. (2020)

Miller, L. (2020)

and endnote gives me this:

Miller, S. (2020a)

Miller, L. (2020b)

Even though these are different authors. What can I do?

Thank you very much in advance!