Only kbin users are seeing what you see. It looks fine on other Lemmy instances.
Lemmy and kbin do weird things with code blocks. From the source, the post itself clearly only contained backticks. Lemmy sends out marked-up text. kbin escapes it.
curl -i -X GET -H 'Accept: application/activity+json' https://lemmy.cafe/comment/1368187
https://en.m.wikipedia.org/wiki/ReiserFS