Fonts missing in Linux (though available to other software)
After a complete reinstall and upgrade of Ubuntu (to LTS 18.04, Linux 4.15) I've tried to recover all the previously installed fonts. No problem at all until I've tried to recover Vollkorn family. At first no one of them downloaded from https://www.1001fonts.com/vollkorn-fo... appeared on my LibreOffice Writer 6.0.6.2. After lots of tries, automatically installing them with the GNOME Font Manager and manually copying to the various fonts related paths both for the user and for the system, I only got "Vollkorn", "Vollkorn Medium" and "Vollkorn Semibold" to appear on the drop-down font menu at Writer or Calc.
All other Linux applications (Gimp, etc.) seem to get them without a problem. I even tried to install some older versions from the official author site: http://vollkorn-typeface.com/ ...and no way.
I've done all recommended things: update font system cache, closing and opening again LibreOffice, restart session, reboot computer... and no matter what I do, all other font sizes of this family are missing. We MUST work with one of them (Vollkorn Bold) but it's still missing from LibreOffice.
I even uninstalled GNOME font manager because after so many tries it seemed to get frozen anytime I opened it. Maybe there's some corrupted installation or something related to these font files???
Thanks in advance to anyone who can give us some clue on this frustrating problem!
What is the font technology (TrueType, OpenType, …)? Is the technology the same for all variants? I've read somewhere that recent LO has dropped support for "older" font technology.
I've tried with both TTF and OTF, with the same result :-(