Plex server doesn't recognise HEVC videos in m4v container

[g000phy]

I have a server running just fine on FreeNAS. Except for one problem - it seems not to be able to recognize any HEVC m4v file. It plays HEVC mkv. It plays AVC in m4v or mp4. But after remuxing the same file to m4v (or mp4) container - the server immediately stops seeing it as a supported file.
The files themselves are just fine - can be played by all players including QuickTime. Naming is also not changed. The problem appears to be in combination: codec + container.

My goal is to have files recognizable by any software i.e. QuickTime and Plex. So I need help fixing Plex.

Server Version#: 1.18.3.2129 (latest available as a FreeNAS plugin).
Player Version#:

[anon18523487]

Plex should not have an issue seeing the file. Can you update your library then send me the scanner log? Also, let me know what file it is?

[g000phy]

Not sure which log you meant. Plex Media Server Logs_2020-03-01_11-11-30.zip (4.6 MB)

It’s not a file, it’s files, lots of them that I don’t see. As an example the screenshot from Plex and the list of files:

[g000phy]

Seem to solve the problem. FreeNAS switched to ACL and it messed up the permissions. Had to redo them completely and new stuff started to appear. Hooray =)