I really struggle to find decent modern cdramas.

I watched and dropped :

The Day of Becoming You

Love is Sweet

As Beautiful  as You

Go Ahead and Hidden Love were ok  and I enjoyed Best Choice Ever except it was more of a family drama which ruined Go Ahead too for me. 

Now I want something modern with more drama, more serious relationships, less comedy and good looking and well thought out characters please. 

Have you tried You Are My Secret.  I'm only 7 episodes in but I like that the couple is mature, there's a business/work setting that they have to navigate as a couple in secret.  I like that they look and act like mature  adults.  It's the first C Drama in a while that's held my attention.

Definitely 'Will Love in Spring '. I really loved it. 'The Tale of Rose' i heard was also decent and 'To the Wonder ' is probably top contender for my favourite short length drama this year. 'Meet Yourself ' was also a good watch  starring the FL of 'The Tale of Rose' and the ML of 'Will Love in Spring' lmao

Put Your Head On My Shoulder

Dine with Love

I Know I Love You

Crush

Le Coup de Foudre

Somewhere Only We Know

Unrequited Love (2019)

Edit: Most of these have somewhat lower ratings but I really liked all of them

 emeraldarrows:

Lighter & Princess 

Tried this 2x but I can't get into it. 

 maidenholmes:

Put Your Head On My Shoulder

Watched few eps, but it gets tragic no? 

Forever Love (2020)... more on the light/comedic side but with serious parts too.

 MarkJason:

Watched few eps, but it gets tragic no? 

Absolutely not! Put Your Head On My Shoulder remains positive and downright sane throughout with likeable characters, While the ML overthinks how to express his feelings towards the FL - and takes far too much advice from far too many people - he never doubts them.