I'll start off by saying this story isn't up my alley at all so take whatever I say with a grain of salt.
The main issue is that it never caught on to any kind of following. Even the first chapter has 16 views. That's really not enough to draw any useful conclusion from even if all 16 stopped reading so really your concern first and foremost should be why people aren't picking it up in the first place then if you manage to get at least 100+ people to read your first chapters you can see where they are dropping off and get a better idea what was happening in the story around that point as possible causes.
I think what
@Succubiome and
@Roseofblades have said cover most of the big things.
You are writing what is probably the least popular romance coupling on this site. I don't have the numbers, but from regularly checking out rankings my guess would be the popularity goes as follows(most popular to least):
GL(often with GB mixed in to appeal to straight men and women)
Male MC & Female Lead
BL
Female MC & Male Lead
Also solely romance focused stories aren't very popular on SH. Sure the majority of stories on here probably have romance elements, but generally they will have a rather large actions, adventure, fantasy, or science fiction aspect too. So you are already fighting an uphill battle to get an active following on SH for this particular story.
You will also want things to hook people, that can be an interesting title, cover or synopsis. I agree with Rose saying all of them feel kind of bland which is probably making the already limited audience not pick it up which is something you definitely can't afford when your target audience is probably already one of the smallest on the site.
For the synopsis it feels too much like it's a recap of too much of the story. You want people to feel like they are intrigued, but need to actually read the story to find out more. Yours is making me feel like I have probably read spoilers for your story that will probably spoil some things if I decide to read it. Tis could very well be a reason why people are dropping off if this is actually the case. Why would I read it if I already know all the big twists and turns that are coming?
For the title something more descriptive would be good. Now this is just from the synopsis so it might not actually work and which fits best would depend on which elements are actually major parts of the story however titles in a direction that might work better on SH would be:
Undercover in China(if the NSA elements are strong)
Lost in China's Hollywood/Rising Star in China(if the being a rising starlet after moving to China is a big focus)
Think things that kind of tease what to expect without even having to check out the synopsis. You want people to actually click on your book after all and the way to do that is to stnd out from the other books by title and cover image first.
Now generally the recommendation here would be put a hot anime woman on the cover for a lot of books on SH, but I doubt that would work since your novel isn't really the type that those covers appeal to. This means the cover needs something else to catch the attention though. It sounds like maybe having a glamorous life is the fantasy that your story will be fulfilling. If so having a cover that portrays that would probably be better. So showing a woman in a fancy dress at some high class party of some sort would probably work better than just a somewhat cute girl wearing basic clothing with a nondescript background. Maybe incorporate some Chinese elements into the cover.