Nixie sits next to 4 phonetic neighbors — Pixie, Trixie, and Dixie are the closest matches by sound. Most share Nixie's Germanic cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"water sprite, fairy of rivers and lakes"
"grace meadow"
"dark, black"
"son of Maud, mighty in battle"
"land desiccated from water"
"from the green meadow"
"hazelnut"
"high tower, elevated"
"supernatural being of power"
"son of Cadan (fighter)"
"of noble birth"
"muddy, boggy (alternate etymological theory)"
"stone, dweller near stones"
"the Lord is my God"
"fairy, sprite"
"well-mannered, polite, graceful"
"little rose, rose garden"
"lake, waterfall"
"elf power, supernatural strength"
"Yahweh is merciful"
Similar sound: These names share phonetic patterns with Nixie — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Germanic origins, giving them the same cultural heritage as Nixie.
Rhythm: Nixie is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.