Vandra sits next to 4 phonetic neighbors — Sandra, Wanda, and Vonda are the closest matches by sound. Most share Vandra's Slavic cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"Defender of men; variant of Sandra from Alexandra"
"Judged; vindicated"
"brooding, sullen"
"rose lady; a woman of roses"
"Judge; one who judges"
"blessed"
"captivating, one who binds others"
"Possibly related to sword or fire brand"
"Free one; from France"
"fire, burning flame, passionate blaze"
"possessing goodness"
"follower of Dionysus"
"follower of Christ, anointed one"
Similar sound: These names share phonetic patterns with Vandra — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Greek origins, giving them the same cultural heritage as Vandra.
Rhythm: Vandra is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.