Boys dormitory 303 is a good one with multiple bl side coupled and two main ones and basically all the couples are just loser teenage boys in love, it’s super funny and has a lot of fluff and also some smut in it. It has a good storyline (in my opinion) and has short chapters which makes up for how many chapters there are.
If you havnt read it yet, try
https://www.mangago.zone/read-manga/happy_shitty_life/
Not sure if its underrated but i personally havnt seen much talk about it outside its comments section. May or may not be your cup of tea but i assure you theyre both losers and its pretty funny.
any loser x loser funny underrated mangas/hwas? emphasis on the underrated cz my brainrot has convinced me I've gone thru the top ones here ;___;