indeed this looks like your on the development branch instead the normal stable one. This also would explain why your IR is not working anymore since the current kernel in the development track does not load the meson_ir kernel module.
Anyway, first the /etc/apt/sources.list(stable):
deb http://ftp.debian.org/debian stretch main contrib non-free
deb http://ftp.debian.org/debian/ stretch-updates main contrib non-free
deb http://security.debian.org/ stretch/updates main contrib non-free
deb http://apt.osmc.tv stretch main
If you want again join the development branch, add line
deb http://apt.osmc.tv stretch-devel main
If IR support is important for you, you can try to downgrade the kernel to #94 version:
Thanks, but I not sure now if that worked, so I have reinstalled my box.
I did still have the cracking sounds after reloading my config, so after enabling and disabling settings I found the problem. It was stereo upmix which was enabled that was creating the issue with the sound.