Nuki deleting authorization failed

Hello! I use REST API to delete old codes and it stopped working. Now, when I sent a request to delete old code, I see on Nuki WEB the loaded next to this code, and then Nuki deleting authorization failed error.

When I remove codes using Nuki WEB, some of them can be removed, but other return the same problem

It looks like deletion form mobile app works well.

I think the issue started happening after I tried to remove 100 keys using API at once. (= sent 100 requests within couple of seconds).