Although not as common as films that only feature queer side characters or characters just existing (especially in the early days), there are still plenty of films that feature open romances between queer characters as major plot points.
Anders Als Die Andern (Different from the Others) (1919)
Mädchen in Uniform (Girls in Uniform) (1931)
L'air de Paris (Air of Paris) (1954)
Anders als du und ich (Bewildered Youth/ The Third Sex) (1957)
Les Amitiés Particulières (This Special Friendship) (1964)
Utsukushisa To Kanashimi To (With Beauty and Sorrow) (1965)