I know that these verses are bracketed off in the critical texts. But the ESV includes them without comment (in all the various ESVs that I have).
I wasn't seeing any info when I hovered over the word "mystery" in v25, and at first I thought it was a setting problem for that window. So I turned on the inline interlinear, and sure enough, there's no data there whatsoever. It stops at the end of verse 23, and there's a comment about the manuscripts that do include v24.
Is this a bug in the underlying interlinear that L6 is using for the ESV? A side effect (of course) is that "search this resource" using a lemma won't find anything in these verses. My search on g:musterion is what led me down this path.
Thanks,
Donnie