Add missing cards to collection does not work

[cbs38139]

Hi!

i tried yesterday and today: I have a list of cards. When I use the "Add to to collection" - "Only Missing cards" function, it adds them (cards now have a green check mark). If I close the browser and open it again, it looks like these cards have not been added to the collection (no green check mark).

Am I doing something wrong? Could you please help?

Thanks You!

P.S.: Here is the list of cards:
https://deckstats.net/decks/117371/2958112-cleanup/en

[cbs38139]

Now here is the shocker:

This error only shows in Safari on Mac OS. It shows correctly on Chrome on Mac OS and also shows correctly on Safari on iOS!

Is this a problem with the Safari cache on Mac OS (or something similar)?

[cbs38139]

Also, I found out that the cards did actually get added.

Since I did not realize it right away, I added them multiple times and needed to manually remove them again from Collection.