*Update on 18 Feb: Corrected an incorrect assumption of mine below. The count correctly increases on the next day, but the circle still starts out showing as full in the app/Goal completed on the web.
*Post updated on 17 Feb with new information, screenshots, and a video recording
I am posting this in iOS bugs since I’ve been using only iOS for reviewing and learning, but this issue has to do with the data, since I see it on the web as well.
For the past 6 days, including today (i.e. since 12 Feb), Memrise has not been resetting my steak.
My streak counter for my courses (all are community courses, if it matters) have remained a full, shaded, dark blue circle (in the iOS app), and as “Goal completed!” (on the Memrise website).
Concretely, for each course, my X-day streak has remained as an X-day streak for the past 6 consecutive days, even though by now it should have been X+6 days. (Or, if I was unluckier, maybe it would have gone down to 0.) Update 18 Feb: Actually, since I took the screenshots yesterday, I discovered that on the next day, the count actually does increase, but it still starts off as a full circle (on the app) and “Goal completed!” on the website. My apologies for the confusion, as I don’t really pay attention to the individual numbers anymore. 
This is not an issue with the information not being fetched or a delay in updating the UI. After I complete my daily goal on the app (which is 1500 pts for these courses), nothing changes. Also, on the second or third day of this happening, I opened up the Memrise website just to check the status before I started on my daily review, and it also said “Goal completed!”
I have one course that I’ve completed and have maybe a couple of words come up for review each day. For that course, I never have enough points to hit the goal, so it’s always a partial circle. I notice that this circle correctly resets the points progress every day (remains as 0-day streak, and at the start of the day, the circle is light blue and completely unfilled):
After reviewing some words:
What I usually do is review, with the occasional learn new words. When I start, my progress is full:
If I earn less than my goal of 1500 points, the circle shows the progress, but the streak reduces by 1 (note the timestamp, the screenshot above was taken before this one):
BUT this is just visual. On the website, it still shows as “Goal Completed!”, and if I switched to another course and back to this one, it will show a full circle with a 9-day streak again.
Watch a video recording of the full behaviour. I switch between the app and the website to show what is displayed on each.
(Once I hit the goal of 1500 points in a day, the circle is always full no matter I switch courses or earn more points.)
The partial thing progress that regresses the streak by 1 also applies to learn (this screenshot was taken on 16 Feb, the day before):
As stated, I’m using iOS. iOS version is 13.3 (not the latest 13.3.1).
My Memrise app version is v3.1.19, last updated on 4 February:
When I checked Memrise’s app page on the App Store, I realised that the latest version is v.3.1.21, released 4 days ago. Like the last time, this latest update (in fact the last two) does not appear in the Account overlay that lists the available updates to my installed apps.
Separately, I saw this post and I don’t know if it is related or not, since OP doesn’t describe exactly the problem in detail, but it possibly could be.
Regardless, this is a bug because even if there was a change to only give out streaks for learning new words, my streaks should have been reset, and not frozen the way they are now.
As for why it took 5 days to post this, it was because in the past I’ve had experiences where Memrise freezes everyone’s streak for a day because of server issues. I thought this was some incident that affected everyone, and ignored it since I also use Memrise a lot less these days. Until I finally checked with someone I know IRL who also uses Memrise, and they said that their streaks were resetting just fine, but that they noticed some time ago that they had to learn new words to keep their streak going.
