suggest me space opera (with strong cultural exploration and character/relationship development)

I think that space opera is the genre term, anyway?

Something like Lois McMaster Bujold‘s Vorkosigan Universe (Aral & Cordelia!), Sharon Lee & Steve Miller‘s Liaden series (especially the earlier novels).

I am familiar with but was less keen on Honor Harrington (I think I was missing the strong cultural details / cultural contact / interpersonal relationship development of the Vorkosigan/Liaden universes?) and Anne McCaffrey‘s „Ship who…“ books are okay but not as good as the first two. Leckie I’ve read and liked but did not love, same with the Alliance–Union universe by C. J. Cherryh. Alas Jack Campbell‘s Lost Fleet did not vibe with me, neither did Murderbot or Winter‘s Orbit. I am currently struggling through Blish‘s „Cities in Flight“ novellas but to be honest in my opinion they are like the antithesis of strong or believable character development.