Activating the effect of Tellarknight Constellar Caduceus does not allow you to banish Constellars as stated on the card.
Bug reproduction steps
XYZ summon Tellarknight Constellar Caduceus using Deneb and Lyra. Activate the effect to banish one tellarknight or constellar monster.
Screenshot OR error code
Should be able to select the constellars that are in my deck as well as the old tellarknights. Only the OCG cards are able to be banished as part of the effect.
What OS are you using
Tellarknight Constellar Caduceus effect
2+ Level 4 monsters
If this card is Xyz Summoned: You can target 1 “tellarknight” card and/or 1 “Constellar” card in your GY; add them to your hand. You can banish 1 “tellarknight” or “Constellar” monster from your hand or Deck, then detach 1 material from this card; this effect becomes that banished monster’s activated effect when that monster is Normal Summoned. You can only use each effect of “Tellarknight Constellar Caduceus” once per turn.