Does this sharp under the chord mean to play a major chord?

Question

The source is p.95 in...

Plain-Song (Helmore, Thomas) https://imslp.org/wiki/Plain-Song_(Helmore%2C_Thomas)

...and the particular sharp is this one highlighted in yellow...

It confusing, because all the other accidentals under the score match up with an accidental in the chord above, and IF the sharp means play a D major chord, that would raise the second degree in Phrygian, which seems to un-do the Phrygian-ness of the music. (It sounds nice to me either way D major or minor.)

---

EDIT

I didn't mention musica ficta specifically, but I think this should be added.

https://en.wikipedia.org/wiki/Musica_ficta#Modern_editions

In the Renaissance accidentals were not written in the notation, but in performance they were used and the practice was called musica ficta. Modern notation shows where those accidentals go above notes not on the staff.

This accidental below the note looks similar to the modern notation for musica ficta. The confusing things is how some of those accidentals are given both on the staff and below. This particular sharp is not on the staff, only below.

If I treat it like a kind of modern notation of musica ficta, I would apply the sharp.

Figured bass

http://robertkelleyphd.com/home/figured-bass/

It probably is more obvious to say the accidentals below the staff are in the same place as the figured bass symbols. A sharp alone in figured bass means to play a major third.

Answer 1

I suspect it's a typo, and the # sign in basso continuo was supposed to be under the consecutive chord, the last one in the first system.

Accidental under the bass note means the chord contains a note third above the bass note and it has that accidental w.r.t. diatonic note.

The notation as it is contradicts itself. In the marked chord the top note is F, which is diatonic in E-phrygian, while raised third from the bass note D is F#. There shouldn't be # mark below the chord. In the consecutive chord the bass note is E, above which there is a non diatonic third G#. There is a missing # sign below the chord.