https://dragonlance.fandom.com/wiki/Knights_of_Solamnia
MEMBERSHIP IN MULTIPLE KNIGHTLY ORDERS
Knights of Solamnia are only ever members of one of their organization's orders. In the course of their training, most knights begin as members of the Knights of the Crown and then move on to join other orders. Whether a character follows this path or another, they retain what they learned as a member of an order even if they join another. Characters can change what knightly order they're a part of, but they always have access to any Knight of Solamnia feats they've acquired.
https://media.wizards.com/2022/dnd/downloads/UA2022HeroesofKrynn.pdf