
This is with the pretty wide age gap
https://www.mangago.zone/read-manga/gotou_san_wa_ore_wo_kaitai/ (megane sensei aka wotakoi's author hahaha amazing art)
https://www.mangago.zone/read-manga/come_to_hand/ (cute older uke and heart warming)
This one is sho ai (i reaally love amamiya sensei's work) https://www.mangago.zone/read-manga/blue_blue_blue/
But it has a yaoi dj https://www.mangago.zone/read-manga/blue_blue_blue_dj_after_story/
My other younger seme x older uke tag doesnt has a wide gap like those links hohoho

Some more:
https://www.mangago.zone/read-manga/koi_wo_suru_tsumori_wa_nakatta/ (suzumaru minta sensei's art is just- *chef kiss*)
https://www.mangago.zone/read-manga/itadakimasu_gochisou_sama/ (puppy seme bahaha)
https://www.mangago.zone/read-manga/hadaka_yori_mo_oku_fukaku/ (i love the lift scene when they were touching each other's pinkies in secret ehe)
https://www.mangago.zone/read-manga/my_housemate/ (for manhwa /just realized most of my readings are mangas)
https://www.mangago.zone/read-manga/egotism_heat/ (omegaverse and imo this is a rare plot which i found interesting)

You are welcome (づ ̄ ³ ̄)づ if you want to look more of age gap you can search it through https://www.mangago.zone/tag/ and type 'older uke'. Those recommendations from me are just the ones ive found it worth to reread (⌒▽⌒)

https://www.mangago.zone/home/mangalist/798019/
If you want some !
This is not related to the story but does anyone have age gap yaoi stories to recommend?