Under the Moonlight

the 2 main leads solve cases for the government. one is a detective one is not but their bickering and banter keep you engaged

Same Ming Dynasty setting, it tells a story about an austistic Shuai Jia Mo, who is obsessed with mathematics, stumbles upon a historical problem in Jinhua County, he's met with multiple obstacles in his attempts to correct the mistake, triggering a tension between various stakeholders.

Both dramas are set in the Ming dynasty and are focused on the "small folk" (notably constables, prostitutes).
Ripe Town is a short series that revolves around a single case, while Under the Moonlight is a longer series that feature 10 different cases.

Both dramas share some cast members, including a child actor Yu Yao who plays a tragic character in Ripe Town but shines with his comedic delivery in Under the Moonlight.

The story in Ripe Town doesn't have a romantic storyline while Under the Moonlight features a love triangle (but this drama is one of the rare cases where it's done well)

Overall, Ripe Town has better cinematography and tighter writing but Under the Moonlight, despite being a lower budget project, punches way above its weight.

Both have strong FLs who were sold off by their families/people and worked hard to rise above their fate. Both MLs are good hearted, wealthy, and devoted to the FL. Both dramas have a similar realistic and serious tone and style.

Investigating mystery from the past - dealing with manipulations and machinations of rich and powerful - mature love - a closer look at lower- and middle-class life

Zhai Zi Lu also played the immature young master in Under the Moonlight, though he is giving a different enough performance in Cases Between Us to distinguish between the two. They both also feature corruptions in power in local governments, institutions, and strong families vs the people, class, and women's injustices.