Infrastructure:
Libreelec is version 9.2.6. Kodi is version 18.9
All was running fine and fast - no problems so far.
Yesterday I did an update (apt-get dist-upgrade) on my fileserver (Debian Bullseye).
After the update, playing movies with Kodi from the NFS shares was stuttering and I had jumps and rendering-artifacts.
I tried to reduce NFS-version to version 3 on server, with no result.
Than I mounted the shares with SMB (Kodi-build-in) and (on the intel NUC) NFS manually. With these mounts all runs fine, without hickups, artifacts or what so ever.
I think the problem is Kodi build-in libnfs? Seems to have problem with "newest" NFS-server-version?
Can anyone help?
EDIT: Seems to be a kernel-problem: https://github.com/xbmc/xbmc/issues/19147
From kernel 5.10.11 to 5.10.15 there is a bug. If you can't wait for the new kernel, build you own.
Here a little documentation with Debian:
apt-get install linux-source-X.XX
apt-get install libdev libelf-dev libssl-dev m4 debhelper dpkg-dev dwarves
mkdir ~/kernel
cd ~/kernel
tar xavf /usr/src/linux-source-X.XX.tar.xz
cp /boot/config-X.XX ~/kernel/linux-source-X.XX/.config
nano ~/kernel/linux-source-X.XX/.config
### change CONFIG_SYSTEM_TRUSTED_KEYS=""
### change #CONFIG_SYSTEM_EXTRA_CERTIFICATE
cd linux-source-X.XX
make oldconfig
nano net/sunrpc/svcsock.c
### change at nearly row 1113 see link below
make -j 3 deb-pkg LOCALVERSION=-yournamehere KDEB_PKGVERSION=$(make kernelversion)-1
cd ..
dpkg -i linux-image-X.XX-yournamehere-1_amd64.deb