Unable to stream using Widevine Widevine



I have installed latest Kodi release for webOS (Kodi 21) on my new LG Smart TV.
All is working fine except the streaming of some TV channels like LA7 (plugin://plugin.video.wltvhelper/play/la7/La7) due to an error on Widevine libraries.
At first run I was prompted to install Widevine CDM. After downolading 1.3 GB Chromium OS, the package was automatically extracted and Kodi reports that the installation was completed succesfully.
When I try to stream LA7 channel now I get an error and the tips suggest to check in the kodi log for fixing.
Here there is the kodi log: kodi.log

The first critical entry is

Code:
critical <general>: [script.module.inputstreamhelper] Failed to check for missing Widevine libraries.

but I can confirm that the libraries are installed since I can see, browsing the filsystem, this file

Thanks for helping

path:
/media/developer/apps/usr/palm/applications/org.xbmc.kodi/.kodi/cdm/libwidevinecdm.so