Plex sometimes ignores my file

For some reason, the occasional file won’t be picked up by plex, even after several restarts, reboots, ‘plex dances’, etc.
The file I’m currently having problems with is a 4K version of a movie I have two versions for. See below:

\Movies
\MOVIETITLE (2016)
\Trailers
etc.
MOVIETITLE (2016) (4K).mkv
MOVIETITLE (2016) (10bit 1080p).mkv
MOVIETITLE (2016) (1080p).mp4

All files are H.264+AAC. It picks up the bottom two (I’ve had these for a while).

Wouldn’t be the first time I’ve had this problem.

Instead of using ( ) for all that extra, try putting it in brackets instead [ ].

@Peter_W said:
Instead of using ( ) for all that extra, try putting it in brackets instead .

In the folder path as well?

Nope. Still Unsuccessful.

I tried:
\Movies
–\MOVIETITLE [2016]
----\Trailers
--------etc.
----MOVIETITLE [2016] [4K].mkv
----MOVIETITLE [2016] [10bit 1080p].mkv
----MOVIETITLE [2016] [1080p].mp4

Yes, sorry for the ambiguity. I meant the 4K, 10bit etc. The years should still be within ( ). A Plex dance is also as has been stated needed.

Nope. Still Unsuccessful.
I tried:
\Movies
–\MOVIETITLE (2016)
----\Trailers
--------etc.
----MOVIETITLE (2016) [4K].mkv
----MOVIETITLE (2016) [10bit 1080p].mkv
----MOVIETITLE (2016) [1080p].mp4

I should note that I have been using the model posed in my original question for other movies where it works perfectly, until this one.

I fixed the problem:
For some reason, the file I had copied over had a size of 0KB. When I went back to the original file it was 6GB. I wonder why it didn’t copy the file but copied a placeholder. My original naming method works now.

Thanks @Peter_W and @flow for your help.
Would any of you be able to provide input on my other discussions?