Sometime around snapshot 20250102 I started having issues with Flatpaks not using system fonts or cursors. Most notably in DBeaver and Zen Browser. If you have these issues, you can solve them as below.

Github issue

1. Download the previous RPM from the Tumbleweed repos: https://download.opensuse.org/tumbleweed/repo/oss/x86_64/xdg-desktop-portal-1.18.4-1.1.x86_64.rpm

2. Open the location you downloaded the RPM in a terminal and run: sudo zypper in --oldpackage xdg-desktop-portal-1.18.4-1.1.x86_64.rpm

3. (optional) Lock the package version to skip the bad version: sudo zypper al xdg-desktop-portal

Note: once a newer package is released, you can remove the package lock with sudo zypper rl xdg-desktop-portal

Zypper Cheat sheet