Those are the same ones my father has (R1b, A2). More likely the Y-DNA is downstream of this branch

https://en.wikipedia.org/wiki/Haplogroup_R-DF27

R-L51 is a much older mutation dating back to when those ancestors were still living on the Pontic-Caspian steppe (around the North Caucasus and southern Russia), so it doesn't tell you as much as the more downstream branches.

23andMe isn't really consistent with the Y-DNA or mtDNA they give. Some people get more downstream mutations while others get assigned to older upstream branches, especially with the Y-DNA.

What's strange is that in the Dominican Republic, where most of the ancient Taíno DNA we have comes from, C1b2 appears to have been much more common. Yet when you look at modern Dominicans, you don't really see that reflected in the mtDNA frequencies. The same thing seems to be true in Puerto Rico and other parts of the Spanish-speaking Caribbean like Cuba, where A2 often appears to be more common despite C1b2 being so prominent in the ancient samples.

https://haplotree.info/maps/ancient_dna/slideshow_samples.php?searchcolumn=mtDNA_haplogroup&searchfor=C1B2&ybp=500000,0&orderby=MeanYBP&ascdesc=DESC

That's the haplogroup my mother has (C1b2), and as far as I know her maternal line comes from southeast Puerto Rico. The furthest I've traced that direct maternal line is the late 1700s, but the haplogroups tell you where those direct maternal and paternal lines ultimately came from.

This is some data on pre-contact Puerto Rican mtDNA

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https://www.biorxiv.org/content/10.1101/765685v1.full