From doing some testing locally, it seems like this might be another side effect of the regression introduced in 7b9b74bee (in addition to T395701, T395640, maybe T395973, & possibly others). Given that a patch to resolve this issue (https://gerrit.wikimedia.org/r/1152331) was merged on June 4, this would also match up with what @Willy1018 noted (in the task that got merged here) about this issue not currently occurring on the Beta Cluster.

Given the impact this regression seems to be having, I'll look into whether it's possible to get the fix backported on Monday (rather than having to wait for it to be rolled out with the weekly deployment train).

In T396233#10893604, @A_smart_kitten wrote:

Given the impact this regression seems to be having, I'll look into whether it's possible to get the fix backported on Monday (rather than having to wait for it to be rolled out with the weekly deployment train).

A backport didn't end up happening, unfortunately :(
That being said, the patch should now be live on zh.wikipedia, and I don't seem to be able to reproduce the issue myself any more -- @Diskdance @Willy1018 please could you confirm whether this issue still exists for you?

In T396233#10918061, @A_smart_kitten wrote:

@Diskdance please could you confirm whether this issue still exists for you?

I can confirm this issue has been fixed on Chinese Wikipedia.