Reported by Cooltey: Has en and zh-tw. In today's explore feed both show Top Read, but when scrolling down to prior days only English is shown.
I haven't been able to reproduce so far. I've been testing with both en and zh-tw and ja, on a fresh install of Testflight 6.8.1 (1813). I notice the Explore feed does continue to fetch previous when you scroll down to the bottom, and if you come back after several days it does not fetch intervening days, which is the opposite of how we originally thought this worked.
I tested by setting the device to a date in the past, scrolling through the feed and confirming I see Top Read for both languages, and at the bottom upon fetching previous days I continue to see Top Read cards for both. Then I changed the device date to a current date, wait for the Explore feed to refreesh by either pulling to refresh or terminating and relaunching, and confirming I see Top Read cards for both on the current date. I can hide Top Read if I turn it off for zh-tw or ja in the Explore feed settings, which is expected. Maybe this is more of an edge case bug where that setting is somehow getting toggled when it shouldn't be.
I also tried testing via an upgrade from 6.7.4 to 6.8.0 (where a zh language preference upgrades to the more specific zh-tw language preference), and tried adding zh-tw as a preference a week after a fresh install. In this case Chinese cards aren't shown at all during the window of time where we've already fetched in the past, but it will populate and show again if we scroll so far down that it has to fetch en as well.
@cooltey are you still seeing this bug on your device? If so, can you check the Explore feed settings and see if Top Read is turned off for these languages? Also, can you let me know what language and region you have set up in device settings (General > Language and Region)?