Hello, i'm gentoo user, i use testing ebuilds (all). I use gentoo with plasma during now long time ago, and now i have little problem. But i don't found any patch. When i would like to change for example sddm theme, preview are visible, but when i would like to change wallpaper and do research, all wallpapers preview isn't visible, i have just rects...

Links with gentoo report and screenshots: https://forums.gentoo.org/viewtopic-t-1113126-postdays-0-postorder-asc-start-0.html

It's strange because, when i change to other setting, previews are visible 1 second (read topic)

STEPS TO REPRODUCE
Just emerge normally plasma-desktop and others essentials package

OBSERVED RESULT
Wallpapers preview isn't visible

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Gentoo - Kernel 5.7.7
KDE Plasma Version: 5.19.3
KDE Frameworks Version: 5.71
Qt Version: 5.15.0

ADDITIONAL INFORMATION

zohran@MSI-GS73VR-6RF ~ $ emerge --info
Portage 2.3.103 (python 3.7.8-final-0, default/linux/amd64/17.1/hardened/selinux, gcc-10.1.0, glibc-2.31-r5, 5.7.7-gentoo x86_64)
=================================================================
System uname: Linux-5.7.7-gentoo-x86_64-Intel-R-_Core-TM-_i7-6700HQ_CPU_@_2.60GHz-with-gentoo-2.7
KiB Mem:    16278096 total,  12720012 free
KiB Swap:   20971516 total,  20239868 free
Timestamp of repository gentoo: Fri, 10 Jul 2020 14:30:02 +0000
Head commit of repository gentoo: 7d197240b806daa3898e8a32fa9dd58ccaa999a7
sh bash 5.0_p17
ld GNU ld (Gentoo 2.34 p4) 2.34.0
app-shells/bash:          5.0_p17::gentoo
dev-java/java-config:     2.3.1::gentoo
dev-lang/perl:            5.30.3-r1::gentoo
dev-lang/python:          2.7.18::gentoo, 3.7.8-r1::gentoo, 3.8.3-r1::gentoo, 3.9.0_beta4::gentoo
dev-util/cmake:           3.17.3::gentoo
sys-apps/baselayout:      2.7::gentoo
sys-apps/openrc:          0.42.1::gentoo
sys-apps/sandbox:         2.20::gentoo
sys-devel/autoconf:       2.13-r1::gentoo, 2.69-r5::gentoo
sys-devel/automake:       1.15.1-r2::gentoo, 1.16.2::gentoo
sys-devel/binutils:       2.34-r1::gentoo
sys-devel/gcc:            10.1.0-r2::gentoo
sys-devel/gcc-config:     2.3.1::gentoo
sys-devel/libtool:        2.4.6-r6::gentoo
sys-devel/make:           4.3::gentoo
sys-kernel/linux-headers: 5.7::gentoo (virtual/os-headers)
sys-libs/glibc:           2.31-r5::gentoo
Repositories:

gentoo
    location: /var/db/repos/gentoo
    sync-type: rsync
    sync-uri: rsync://rsync.gentoo.org/gentoo-portage
    priority: -1000
    sync-rsync-verify-max-age: 24
    sync-rsync-extra-opts: 
    sync-rsync-verify-jobs: 1
    sync-rsync-verify-metamanifest: yes

fulgurance-overlay
    location: /var/lib/layman/fulgurance-overlay
    sync-type: laymansync
    sync-uri: https://github.com/fulgurance/fulgurance-overlay.git
    masters: gentoo
    priority: 50

ACCEPT_KEYWORDS="amd64 ~amd64"
ACCEPT_LICENSE="@FREE"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-march=skylake -O2 -pipe -mmovbe -mmmx -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -mpopcnt -mavx -mavx2 -maes -mpclmul -mfsgsbase -mrdrnd -mfma -mbmi -mbmi2 -mf16c -mrdseed -madx -mprefetchwt1 -mclflushopt -mxsavec -mxsaves"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/lib64/libreoffice/program/sofficerc /usr/share/config /usr/share/gnupg/qualified.txt"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/dconf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo"
CXXFLAGS="-march=skylake -O2 -pipe -mmovbe -mmmx -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -mpopcnt -mavx -mavx2 -maes -mpclmul -mfsgsbase -mrdrnd -mfma -mbmi -mbmi2 -mf16c -mrdseed -madx -mprefetchwt1 -mclflushopt -mxsavec -mxsaves"
DISTDIR="/var/cache/distfiles"
ENV_UNSET="DBUS_SESSION_BUS_ADDRESS DISPLAY GOBIN GOPATH PERL5LIB PERL5OPT PERLPREFIX PERL_CORE PERL_MB_OPT PERL_MM_OPT XAUTHORITY XDG_CACHE_HOME XDG_CONFIG_HOME XDG_DATA_HOME XDG_RUNTIME_DIR"
FCFLAGS="-march=skylake -O2 -pipe -mmovbe -mmmx -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -mpopcnt -mavx -mavx2 -maes -mpclmul -mfsgsbase -mrdrnd -mfma -mbmi -mbmi2 -mf16c -mrdseed -madx -mprefetchwt1 -mclflushopt -mxsavec -mxsaves"
FEATURES="assume-digests binpkg-docompress binpkg-dostrip binpkg-logs candy config-protect-if-modified distlocks ebuild-locks fixlafiles ipc-sandbox merge-sync multilib-strict network-sandbox news parallel-fetch preserve-libs protect-owned qa-unresolved-soname-deps sandbox selinux sesandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr"
FFLAGS="-march=skylake -O2 -pipe -mmovbe -mmmx -msse -msse2 -msse3 -mssse3 -msse4.1 -msse4.2 -mpopcnt -mavx -mavx2 -maes -mpclmul -mfsgsbase -mrdrnd -mfma -mbmi -mbmi2 -mf16c -mrdseed -madx -mprefetchwt1 -mclflushopt -mxsavec -mxsaves"
GENTOO_MIRRORS="ftp://ftp.free.fr/mirrors/ftp.gentoo.org/ http://ftp.free.fr/mirrors/ftp.gentoo.org/ http://gentoo.modulix.net/gentoo/ http://gentoo.mirrors.ovh.net/gentoo-distfiles/ https://mirrors.soeasyto.com/distfiles.gentoo.org/ http://mirrors.soeasyto.com/distfiles.gentoo.org/ ftp://mirrors.soeasyto.com/distfiles.gentoo.org/"
LANG="fr_FR.UTF-8"
LC_ALL="C"
LDFLAGS="-Wl,-O1 -Wl,--as-needed"
MAKEOPTS="-j9"
PKGDIR="/var/cache/binpkgs"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages --exclude=/.git"
PORTAGE_TMPDIR="/var/tmp"
USE="X acl acpi alsa amd64 audit bluetooth btrfs bzip2 compat crypt cryptsetup custom-cflags custom-optimization dbus device-mapper dhcpcd dri dri3 elogind experimental ffmpeg git glamor gstreamer hardened iconv ipv6 jpeg kde kms libtirpc lto lvm mp3 mp4 mtp multilib ncurses networkmanager nls nptl ogg open_perms opengl openmp pam pcre peer_perms phonon pie plasma png policykit pulseaudio readline seccomp selinux semantic-desktop split-usr ssl ssp svg tiff ubac udev udisks unconfined unicode uvm v4l vaapi vdpau vorbis vulkan wayland wifi wireguard wireless x264 xattr xtpax zlib" ABI_X86="64" ADA_TARGET="gnat_2018" ALSA_CARDS="hda-intel" APACHE2_MODULES="authn_core authz_core socache_shmcb unixd actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" CALLIGRA_FEATURES="karbon sheets words" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="aes avx avx2 f16c fma3 mmx mmxext pclmul popcnt sse sse2 sse3 ssse3 sse4_1 sse4_2" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock greis isync itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf skytraq superstar2 timing tsip tripmate tnt ublox ubx" GRUB_PLATFORMS="efi-64" INPUT_DEVICES="libinput synaptics" KERNEL="linux" L10N="fr fr-FR" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LLVM_TARGETS="NVPTX" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php7-2" POSTGRES_TARGETS="postgres10 postgres11" PYTHON_SINGLE_TARGET="python3_7" PYTHON_TARGETS="python2_7 python3_7" RUBY_TARGETS="ruby27" USERLAND="GNU" VIDEO_CARDS="intel i965 nvidia" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account"
Unset:  CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LINGUAS, PORTAGE_BINHOST, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS