I'm seeing a strange MathJax layout problem on Cross Validated. Here's an example from the "All actions" tab of a user profile, but I've also seen it in the review queues as well.
This display weirdness is not caused by the user's MathJax input, as you can see from the post itself.
I've reported this problem before, when it manifested in the context of the new layouts for sites' front pages. This bug is distinct, because it appears on pages that are not front pages, and are not a part of that initiative.
Davide Cervone suggests "it looks like adding
width:100% in addition to
display:block may be necessary for the uses that appear in flex-box settings, like the "Comments" tab on a user's "Activity" page."
I'm using Chrome 97.0.4692.71 for ARM on macOS v12.1 (Monterey).
It appears that this issue is more frequent on Math.SE. Some examples: