{no major spoilers below - just a bit of can be also found at the synopsis}
The Legendary Life of Queen Lau (2022) - Second it
The Romance of Tiger and Rose (2020) [Bit of supernatural - FL goes to a fictional story in the past. She ends up being a princess who has to get married - but she hates this idea! She can't avoid the marriage, but ML is very tricky and plotting many things - it takes a while for them to fall]
The Sword and the Brocade (2021) [Warning: Harem drama, ML has multiple wives. If you ignore that, there's a great drama. FL ends up marrying her ex-brother in law to raise her sister's son. Nor ML or FL wants this marriage at first and it takes quite some time for them to warm up and fall, alongside many troubles and treasons happening at the harem]
The Love by Hypnotic (2019) [FL is a princess who gets married for political reasons and both FL and ML don't each other at first. Later on they fall, but FL forgot important parts of her past]
Romance of a Twin Flower (2023) [FL enters a tricky situation: she's confused as another woman identical to her, but EVIL. This evil woman has a husband who hates her guts. So FL have quite a journey until ML lets go of his hate to realize she has "changed"]
Intense Love (2020) [modern drama: ML doesn't like FL at first, but they have to get married]
Different Princess (2024) [BIT of supernatural since FL goes to fictional past, but FL ends up married to the villain, so she's scared of him and they don't like each other]
Destined (2023) [ fits your description: leads get married but don't actually like each other, later on they end up falling]
General's Lady (2020) [Leads get married and after a few misunderstandings, they fall]
Legend of Yun Xi (2018) [Leads are not so prone to marry each other and just fall after some time during the marriage]
Decreed by Fate (2022) [Fits your description: leads don't like each other at first, get married and both ends up falling later]
Chef Hua (2020) [Leads are not rich nor royalty, shows their married life but they like each other since the beggining]
A Girl Like Me (2021) [been some time since I've seen it, but shows the leads falling, being engaged and marrying, but ML is not very trustworthy]
Love Destiny (2018) [Bit of supernatural: FL goes to the past. FL assumes the life of a recent dead woamn identical to her, but very EVIL. This evil woman has a husband who hates her guts. So FL have quite a journey until ML lets go of his hate to realize she has "changed"]
My Husband in Law (2020) [Modern drama. FL has a ones-side love for ML and he basically is disgusted by her. After some troubles, ML is forced to marry FL. Their marriage is hard 'cause ML treats FL bad, it takes a long time for ML to love her and to realise it]
Padiwaradda (2016) [FL is grateful for the family that raised her. She accepts to get "swapped" to marry her sister's fiance. ML knows since the beggining and hates FL for lying to him, but FL is very sweet. It takes a while for him to forgive and admit his feelings]