An off-the-top-of-my-head list of canons in the tag set with LGBTQ+ characters/relationships, that I don't think I've seen mentioned yet here:

Darius the Great Series – Adib Khorram – main character is gay (and dates boys in the second book of the series)
John Finnemore's Souvenir Programme Season 9 – Gally/Susanna and Russ/Alex are a historical f/f relationship and a present-day m/m relationship respectively; Newt is canonically asexual
This is How You Lose the Time War - Amal El-Mohtar & Max Gladstone – f/f main pairing
His Royal Secret Series – Lilah Pace - m/m romance (only one character is nominated in the tagset, but he's definitely gay!)
Exit West – Mohsin Hamid – one of the two main characters is a woman who starts dating women later in the book
Loveless – Alice Oseman – haven't read it yet, but the main thing I know is that the MC is asexual! Alice Oseman is also generally really good at representing a diversity of relationships
God’s Own Country (2017) – m/m romance
The Other Two (TV) – one of the two main characters (Cary) is gay; I haven't watched season 2 yet so I'm not sure about other characters
Saturday Night Live RPF – Kate McKinnon <3 <3 <3 and Bowen Yang!