Custom XDG settings in user-dirs.dirs cause Thunar to take over 2 minutes to start up

With ~/.config/user-dirs.dirs configured as below, and with all configured directories existing, opening a new Thunar window takes more than 2 minutes. When it has finally opened, Thunar is as responsive as it should be, and the folder icons relevant to the configured directories are shown correctly. Closing the window crashes Thunar.

With the default or no user-dirs configuration Thunar opens immediately as normal.

I'm using Thunar 1.8.14 with Xfce 4.14 on Linux Mint 20.

# This file is written by xdg-user-dirs-update
# If you want to change or add directories, just edit the line you're
# interested in. All local changes will be retained on the next run.
# Format is XDG_xxx_DIR="$HOME/yyy", where yyy is a shell-escaped
# homedir-relative path, or XDG_xxx_DIR="/yyy", where /yyy is an
# absolute path. No other format is supported.
# 
XDG_DESKTOP_DIR="$HOME/Keep/Desk"
XDG_DOWNLOAD_DIR="$HOME/Keep/Desk"
XDG_TEMPLATES_DIR="$HOME/Keep/Code"
XDG_PUBLICSHARE_DIR="$HOME/Keep/Public"
XDG_DOCUMENTS_DIR="$HOME/Keep/Vocation"
XDG_MUSIC_DIR="$HOME/Keep/Recreation/Music"
XDG_PICTURES_DIR="$HOME/Keep/Recreation/Pictures"
XDG_VIDEOS_DIR="$HOME/Keep/Recreation/Videos"

user@system:~/.config$ time thunar

real	2m20.094s
user	0m0.011s
sys	0m0.007s