Maybe a problem with OSMC related to the encryption and the high resolution?
When you start a livestream your system needs support for Widevine encryption and 1080p50 resolution playback.

You can lower the resolution in the VRT MAX add-on settings to 720p50 in the Playback tab by setting maximal bandwidth to 4096 (Or 3072 for 540p25 resolution)

Maybe a problem with OSMC related to the encryption and the high resolution? When you start a livestream your system needs support for Widevine encryption and 1080p50 resolution playback.

You can lower the resolution in the VRT MAX add-on settings to 720p50 in the Playback tab by setting maximal bandwidth to 4096 (Or 3072 for 540p25 resolution)

Sadly that wasn’t the solution. Even on 2560 the issue remains.

I guess you need to make sure that all components to get Widevine encryption working are installed: https://discourse.osmc.tv/t/how-to-get-libwidevine-working-in-osmc-kodi-19-netflix-disney-viaplay/90848

I can’t seem to get that working either.

osmc@osmc:~$ ./libwidevine_prep_osmc.sh
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package python3-crypto is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'python3-crypto' has no installation candidate

there’s also no way to install python3-crypto…

Try sudo apt-get install python3-cryptography
And see https://discourse.osmc.tv/t/problem-installing-python-crypto-module-dependency-for-netflix-add-on/93713

Having the same issue on osmc.
The following worked for me:

sudo apt-get install build-essential libssl-dev libffi-dev python3-dev
sudo apt-get install python3-cryptography
wget https://github.com/zjoasan/OSMC_libwide_prep/raw/main/libwidevine_prep_osmc.sh
chmod +x libwidevine_prep_osmc.sh
./libwidevine_prep_osmc.sh

I also had the frowny face. I followed @CoderPupil's suggestions. However, for kodi version >= 19 the only relevant thing libwidevine_prep_osmc.sh does is also install python3-ptcryptodome, so I did that manually. Now sporza works!