I would say 'Me Before You' by Jojo Moyes is also a wonderful modern love story novel. Louisa Clark is hired to take care of Will Traynor, a quadriplegic. Their relationship develops in unexpected ways as they learn about each other and fall in love, despite the difficult circumstances.
A great modern love story novel is 'One Day' by David Nicholls. It follows the relationship between Emma and Dexter over the years, checking in on them on the same day each year. It shows how their relationship evolves, from friendship to something more, and all the joys and sorrows that come with it.
'Call Me by Your Name' by André Aciman. It's a modern love story that's set in Italy. The relationship between Elio and Oliver is a complex and passionate one. The author does an amazing job of capturing the intense emotions and the bittersweet nature of first love.