https://www.mangago.zone/read-manga/mister_sama_niwa_nakasarenai/ (No sex)
https://www.mangago.zone/read-manga/pride_ni_kiss/ (Yes sex)
https://www.mangago.zone/read-manga/fake_fact_lips/ (Yes sex, has a sequel)
https://www.mangago.zone/read-manga/junketsu_drop/ (Yes)
https://www.mangago.zone/read-manga/hanakoi_tsurane/ (No sex so far, it's incomplete here, with four more final chapters to come on MangaGo. It's complete on Bato.)
https://www.mangago.zone/read-manga/karasugaoka_don_t_be_shy/ (No sex, has a sequel which I haven't read, I don't know if that one has any.)
https://www.mangago.zone/read-manga/there_s_something_wrong_with_my_popularity/ (No sex. I'm not sure if this counts as rivals to lovers, but it gives that vibe.)
These ones have a decent amount of smut, but the relationships are cute and these men are so dumb and funny. Listing them here if you're ever in the mood:
https://www.mangago.zone/read-manga/you_and_i_can_t_do_this/
https://www.mangago.zone/read-manga/glasses_cloth_and_playlist/
Rivals to lovers bl anyone.. preferably no smut but some is ok