When viewing the comments of an idea in a stream, a comment is being displayed as being written by a user who liked that comment instead of the person who actually wrote the comment. This also occurs after clicking on the show more or show more activity links for an idea in a stream.
For example, User A commented on an idea, then User B liked that comment. After liking the comment, the stream now displays User B as the person who wrote that comment. When you navigate to the idea's page, you see that User A is still listed as the comment author.
This issue was identified as a defect and was resolved in Jive 9.5 and later versions under the code JVHOPST-22646 (The release notes for version 9.5 are available here).
To resolve this issue, please upgrade to the latest version of Jive.