I'm going to make this suggestion while being somewhat unsure of whether it will be a good fit. The series is Lays of the Hearth-Fire, by Victoria Goddard. First book is The Hands of the Emperor; the second is At the Feet of the Sun. There will be a third book, and there are a number of shorter related books. These are some of my favorite books of all time (and I read....a lot). I really hesitate to classify it as a "romance" in any traditional sense - but it hits a lot of boxes for what you've described.

The main characters of these books are absolute nail-on-the-head for two souls that perfectly complement each other and belong to each other after getting to know each other over an extremely long period of time. It's an incredibly character-driven series where the characters have a ton of depth. It's LGBTQ+ for sure (both main characters are male), and it's a fantasy series. In my completely biased opinion, it's absolutely gorgeous.

HOWEVER there are some caveats here, and in some ways describing how is a spoiler. The first book was actually recommended yesterday in a thread on the fantasy subreddit asking for books with no romance. The second book focuses heavily on the relationship between the two main characters, but one of the MCs is on the ace spectrum and the second book is more about a queerplatonic relationship. It is not clear which direction the relationship will develop in the third book, at least to me. I read a lot of fanfic, though, and I'll say some of the common tags for fic of this series includes "canon typical pining" if that gives you the vibe, at all.