You Are My Sunshine (2015)

YAMS is the movie version which despite being quite condensed and sometimes sloppily edited was quite memorable in its own right. I preferred Yang Mi's Mo Sheng and aesthetically on the basest level HXM wins over CW as Yi Chen. Watch after or before the drama... you won't regret it (I watched the film first personally)

Both have a possessive male lead who won't stop until he has the female lead and is very protective of the female lead

Enduring love between two lovers separated over the years but still longing for each other. Through hardship and problems they learn not to let go.

Two lovers separated for years, met each other again. The feelings are strong and they rekindled the romance despite many obstacle facing them.

Both star Yang Mi as the lead female and she is as good as expected.

Both have enduring love as a main theme. There's even a separation of our OTPs with both EL and YAMS. Also a forced/contrived cohabitation after finding each other again.

In both you can feel our OTPs almost unbearable pull towards each other. Male leads in both have amazing chemistry with Yang Mi's characters and both can be forceful and imposing(kissing scenes in both the drama and the movie was scorching) but show their gentle sides too. Huang Xiaoming and Mark Chao both have the most amazing jawlines though Mark is undoubtedly the better actor.

EL had the best soundtrack I've heard in a while but there is also YAMS' OST: Silent by Na Ying that stood out. If you're still hung up over EL give YAMS a try if you have 2 hours to spare.

-Female lead leaves and comes back years later
-FL dads death somehow revolving around ML (wither accurate or not causing misunderstandings)
-Misunderstandings that lead to main characters being apart

They're both based on books written by Gu Man.
Boss and Me is based on the book Come and Eat Shan Shan written by Gu Man;
You Are My Sunshine is based on the book Silent Separation written by Gu Man.

Both the movies have good chemistry between the characters. Simple love stories with not lot of complicated characters.
Both movies have a drama version.
Both the dramas are better than the movies, as you can see the growth in the characters. Would recommend watching the dramas related to these movies as well.