High-profile shows often change character names when it comes to audition scenes to prevent spoilers, and those scenes aren’t even always from the show, but rather written for the audition process only.
It’s worth noting that The Witcher reportedly attempted to avoid spoilers during Season 1 casting by referring to Istredd as “Isaac” and Renfri as “Riley.”
“David” and “Dijkstra” both start with the same letter, and “David” certainly isn’t a name that fits in with a show filled with character names like Geralt, Cirilla, Yennefer, and VIlgefortz.