Not exactly sure when this started, but oversighters cannot see suppressed edits upon clicking the "suppressed user contributions" link. It seems from some minimal testing that //recent// suppressions appear, but older ones do not; I'm not sure where the cutoff is. As an example, I suppressed a single edit in my sandbox just now, but while that appears none of my previous suppressed edits appear; see https://en.wikipedia.org/w/index.php?title=Special:Log/suppress&offender=Amorymeltzer
Alternatively, compare https://en.wikipedia.org/wiki/Special:Log?type=suppress&offender=22.214.171.124 (old, doesn't not working) with https://en.wikipedia.org/w/index.php?title=Special:Log/suppress&offender=126.96.36.199 (new, working).
It seems the error has to do with the `offender` parameter. For an example, searching via target works fine <https://en.wikipedia.org/wiki/Special:Log?type=suppresspage=User%3AAmorymeltzer> but searching revision author with the user who made those edits fails <https://en.wikipedia.org/w/index.php?title=Special:Log/suppress&offender=188.8.131.52> Potentially relatedly, the OOUI inputWidget for Revision Author (i.e. the `offender` parameter) dropdown (`div#mw-input-offender`) does not autofill like the other menus.