New font not showing in Writer

I am running LibreOffice 6.1.5.2 on a Mac OS 10.14.4.
I have added to the system fonts TT-Norms, a new font which is a .otf file. I have reloaded LibreOffice and restarted the Mac (several times), but cannot get the font to show in the dropdown menu. (I have also tried adding the font in the user library.)
The font works in the seperate Textedit program on the Mac and it works in LibreOffice on my Windows laptop.
When I copy text from TextEdit written in the TT Norms font and paste it into Writer, the font is recognized (i.e. it appears under the font name when that text is selected) but I am given an error message saying “the current font is not available and will be substituted”.
How do I get this new font to work properly in LibreOffice on my Mac?

Is the font a TrueType one?

It’s a .otf extension, so I presume an OpenType

I assume you are using the older TT Norms v1.000 from 2017.
Is that correct?

The v1.0 which is available from a bunch of the “free” font download sites is totally messed-up.
The naming fields are a complete jumble - surprised it works at all in LO.
My guess is that LO is so confused it just gives up and assumes it is broken.

The Unique Font Identifier field says it was edited in FontForge.
It is unlikely the TypeType foundry is using FontForge for development.
So it appears that someone who had no idea what they were doing edited the fonts in FontForge.
The fonts would need to be fixed to work properly in LibreOffice, or any other app which uses style groups.

I did check the TT Norms Pro v2.0, 2019 fonts and they look fine.
So I expect they will work correctly.

Update …
I tested the v2.00 fonts on LO Windows and all is working well except the ExtraLight.
See Image below.

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Now if you are already using the v2.000 fonts - I am totally confused.

I would like to know how the v2.000 fonts work on a Mac if you are interested in testing.
The Macs may have some problems with the weight settings, and the multiple weights.
Need some Mac users to test.

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FontForge is a well-known TrueType font editor. I doubt that the problem is about it.

Nothing above says the problem is “about” FontForge.

Thank you for the comprehensive reply. You are correct that I am using v1.0 (which was supplied to me by a developer with some new artwork so I assumed, incorrectly, that it was ok). I will see if I can get v2.0 to try out and report back.
As as aside, the Mac Font Book validation flagged some “minor” errors on installation, but after installation the validation program found no errors.

Unfortunately I’ve been unable to source the V2 files. I’m still puzzled why, if there is a problem with the font, that it works in LO under Windows and not on the Mac. Anyway, I can use Pages on the Mac which works fine so will use that instead for my project. Many thanks for having a look at the problem.

Please check the checkmark at left to accept this answer.
Mac and Windows use different name fields in the fonts so they work differently with broken fonts.
LO does not deal with font anomalies as well as some other apps.

I can send you the fonts if you will test them for me on the Mac, and send me the results.

Sure. If you want to send them over I can have a go at testing them on the Mac, but it won’t be for a couple of days.