Live feed commenting capability for knowledge articles is not supported in Service Portal.
The system property ""glide.knowman.use_live_feed" is not honored.
This is by design of the platform at the moment as live feed based comments display is not supported in Service Portal and there's currently no plans to implement it.
Steps to Reproduce
1. Ensure that the system property "glide.knowman.use_live_feed" is set to true. If it does not exist please create one:
Type: True | False
2. Open an existing KB article in Platform UI (URL of the page starts with kb_view.do), and add a comment to the article.
3. Open the same article in Service Portal, and add a comment.
Expected behavior: Service Portal comments functionality should honor the "glide.knowman.use_live_feed" system property to use live feed commenting capability
Actual behavior: Service Portal comments don't honor the "glide.knowman.use_live_feed" system property and uses its own commenting feature.
There is no possible workaround for this behavior as live feed based comments display is not supported in Service Portal.
Related Problem: PRB1088244