These from Thai PBS:
Sweet Sensory Lovely wee series about friends helping friends with care and respect. Just ignore the way the ML looks at the FL. She can't see it :D
+1 for The Broken Us on quality. Difficult subject matter gently told. A relationship does develop, but it's more about the friendship.
Dream a Little Dream Sweet 1 hour story about a young boy who falls in love with Khon traditional dance
The Rhythm of Life EXCELLENT youth lakorn. High school, so there's some yearning.
Kru Ma Slice of life around a class of 8-9 yos and their unconventional teacher. (Subtitles aren't great but are definitely followable, especially if you have some Thai basics.) One of the young boys has the biggest crush on one of the girls, but it's not developed or given much screen time.
GMMTV: many of the large cast oppressive high school series have something like a relationship tucked in there but they don't get much time. Home School had a few pairs by the end but I remember the one in The Gifted more, probably because that's concentrated into an episode and a half while Home School was more like a few lines here and there.
The Comments Multi-layered, intense, compact five episode youth series looking at the damage social media enables. They clearly took great care over every bit of this, it's amongst the best-crafted work I've seen and articulating a powerful and important message. There's an unrequited crush early on.
I'm Tee, Me Too Begins and ends as light, fan service comedy centered around developing friendships, found family, grief, the complications of parents, and facing your fears with the support of others. There's substance, frivolity, a touch of lakorn and a lot of warmth. One of the story lines involves something akin to romance. It's weak though and easily skipped/overlooked.
The few Netflix series I've tried (Don't Come Home (thriller, mystery), The Believers (cynical and utterly lacking Thai spark), something else I've repressed the memory of) might suit you. They're more Netflix/western than Thai in feel and pacing but if your interest is primarily language learning...
Movies: (* = supernatural)
Heart Attack A close M-F friendship develops, and in other circumstances it might become a romance, but not in these
Bad Genius Real life academic cheating scandal turned into an edge of your seat thriller (if you don't know the outcome) which touches on morals, class and privilege without preaching.
* The Medium SLOW burn horror. Boiled frog experience for me - by the time it was too much for me, I was too hooked to escape.
* Dorm Gentle, sensitive film about a kind boy who befriends a ghost.
Suddenly Twenty Quirky fun but also touching, great use of music. Central to it is a feisty gran and her grandson.
The Trapped 13 IMO the best of the Cave rescue documentaries since it focuses on the boys, their parents and the coach rather than the foreigners to the rescue take of some of the others.
* The Cursed Land Unhurried, - it refuses to rush anything, just layers on the what is going on until it's ready to tell us - atmospheric and creepy. Less horror, and more a particular Thai theme.
By the River Excellent documentary, told in a slice of life manner, about the consequences suffered by Karen people in Klity, Kanchanaburi 15 years on from lead contamination of the river they depend on for food and livelihoods. Beautifully filmed, gentle but powerful, well worth seeking out.