https://www.mangago.zone/read-manga/aoi_haru_kai_ito/
https://www.mangago.zone/read-manga/seven_days/
https://www.mangago.zone/read-manga/neon_sign_amber/
https://www.mangago.zone/read-manga/yondaime_ooyamato_tatsuyuki/
https://www.mangago.zone/read-manga/hana_no_mizo_shiru/
https://www.mangago.zone/read-manga/hinadori_wa_shiokaze_ni_madoromu/
Hope it woks, not sure which type you wanted
these are short and completed bl webtoons. Don't trust my ratings too much because they're pretty harsh
https://www.mangago.zone/home/mangalist/2161916/
Thank you sm<33
Completed yaois with only 15 or less chapters