LibreOffice 7 does not respect GTK theme settings on NetBSD 9.1 + 9.2

[netneo <netneo%proinbox.com@localhost>]

Hello,

I have been unable to get LibreOffice 7 (installed with pkgin) to respect my GTK settings.

I have tested this under both release 9.1 and 9.2. The interface has no theming, just a plain grey Windows 95-style appearance. I have tested this at great lengths on both bare metal and in virtual machines and spent hours looking for a solution, but to no avail.

Screenshots can be found here:

https://imgur.com/vT74UKJ
https://imgur.com/nJHUUfT

Changing (or creating) the gtk3 settings.ini in the appropriate place under ~/.config/gtk-3.0 did not help. 

This has been an issue every time I installed LibreOffice 7, on both 9.1. and 9.2. I have tested this in different environments, such as LXQT, Fluxbox, and XFCE, with no success. Any other application respects my GTK settings fine. Certain systems require that you install a separate package such as 'libreoffice-gtk3' to make it look right, but I haven't found any equivalent in pkgsrc so I suppose it should not be necessary. 

Certain online wikis suggest setting one these environment variables: 

SAL_USE_VCLPLUGIN=gen
SAL_USE_VCLPLUGIN=gtk3
SAL_USE_VCLPLUGIN=kf5

However, this does not have any effect and I doubt this is actually applicable to NetBSD. 

>From online discussions, some users seem to have the same problem while other don't seem to have it at all. I have tried switching to the Libreoffice6 package after uninstalling v7 but that ultimately did not work for me either (upon reboot, the settings seem "lost"). 

Please do not hesitate to let me know what I can do to help you debug this.

Many thanks.
netneo