Closed issue by SpidFightFR on void-packages repository

https://github.com/void-linux/void-packages/issues/46311

Description:
### Is this a new report?

Yes

### System Info

Void 6.5.5_1 x86_64 AuthenticAMD uptodate rrmFFFFFFFF

### Package(s) Affected

flatpak-1.15.4_2 flatpak-kcm-5.27.8_1 xdg-desktop-portal-gtk-1.14.1_2

### Does a report exist for this bug with the project's home (upstream) and/or another distro?

_No response_

### Expected behaviour

Given we grand read access to `~/.themes` and `~/.icons`, and that we enable a specific env var, the selected theme in the env var should be applied (it was up until recently).

### Actual behaviour

Recently, it stopped working, out of the blue, without any reasons. 

I believe it started happening since flatpak-kcm update, but i might be wrong.
QT apps do work as intended tho, so perhaps it is linked to the xdg gtk portal too?

### Steps to reproduce

1. sudo xbps-install -Su
2. Update flatpak-kcm
3. Theme no longer works on gtk apps :(