Just got this bug, I use Firefox. Can confirm the only buff I had prior to this was the Main Shop Discount. It's worn off, but it seems I didn't get that message at all....
I have been getting this event for a few days now. I just chuckled and blew it off, but for me it seems to happen every time the new day on subeta comes around.
I use Opera..i saw a lot of people using other browsers, so I thought i would add mine as well.

Your Quick Feet buff has worn out, back to normal dancing time! 2019-09-15 07:55:02
Same thing, shop bonus wearing off. Has happened every Sunday in September, weird. :P
[Edit] Your Quick Feet buff has worn out, back to normal dancing time! 2019-09-15 21:39:01
Extra wizard quest wearing off.
[edit] Your Quick Feet buff has worn out, back to normal dancing time! 2019-09-16 03:26:01
Shop bonus again~ Not technically Sunday this time :P
Chrome and got the same event with both the main shop discount and bonus wizard quest (got the wizard quest first and then the main shop discount). It didn't display the wizard quest ending event, but did show the main shop discount ending event.
Your Quick Feet buff has worn out, back to normal dancing time! 2019-09-16 15:40:02
Your main shop discount buff has worn out! 2019-09-16 15:40:02
Almost fixed haha.
Just got this today
I've been getting it too. Must've been dancing in my sleep. :D
Your Quick Feet buff has worn out, back to normal dancing time! 2019-09-19 14:44:02
Shop bonus wearing off~
Same problem here! My Shop bonus seems to think I used Quick Feet buff to dance instead.
Edit:
Just got it again today.
|[egg=Amborella]|[tp=Amborella]||||
Got this for the first time: Your Quick Feet buff has worn out, back to normal dancing time!
I had two other events (a ping ive been saving for a day or two and a ‘you have purchases in your shop’ one).
Seeing it on my phone so safari but I usually use Firefox.
Got the event again at 2:13 PM-ish subeta time.

I got it a few minutes ago at the same time my 15% off shop bonus ended.
Hey guys, thanks for the reports and sorry for the delay on this. Since this is just showing the wrong text, not actually breaking functionality, it has been a lower priority thing on our list. But I'm looking into it now and I'll keep you updated! <3
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Ok guys, so a fix has been deployed. Please let us know if that worked. It may take a while for you to get a new event so I am going to leave this open. Make sure that your event wasn't before this post when reporting!
Dexter by ❤
Tankcou bug I must add, It was good practice! Haha
ABCwsHare🐇 Highly seeking
Just got it ... 11 minutes ago.
Not sure but I think probably the end of my 15% off shop discount. It always seemed to be either that or end bonus wizard quest. Chrome user. it says... Version 77.0.3865.90
It may be that all the ones that were set before the fix have to cycle through. At least that is what I am hoping xD
Dexter by ❤
I did quests last night and had the shop % buff, when I logged in this morning I had this. Both this event and the shop % buff event happened at the same time. I came here to report it but saw that it'd already been reported and a fix had been done.

This morning I did more quests, got the shop buff again (after the fix was done) and when I logged back in this evening I had a new one. The buff ended ~5:30 PM EST
