Umm... OP, I'll once again need your help to understand very very vividly from your side here. You know the drill as you've done this: be very detail, throw anything you have in mind, help me retrace your step, relive the moment.
With my best to not lead you to any direction with any prompt, do you mind to tell me as many as you can with what you do when you get the KYC request as below:
[Image snip]
Okay, the KYC request from that image came to me AFTER they asked me to provide simple details: mail, ip, known devices, etc (you can see it in demand letter).
My account was advanced KYC verified prior to this email (to establish that). After I have received this e-mail, I clicked the link and sent the document id again (passport, same picture as in my initial KYC verification, as I had it saved).
After doing that, Sumsub prompted "These documents were used to verify another account" (the black/white image I shown above)
Week or two after, I was informed that my account was permanently banned for breaching Terms of Service.
A tad bit more detailed won't hurt? Like... How long after you get the email did you do the KYC? On which device do you received the email? And I understand correctly you recycle the exact same documents you gave for LuckyWalker69, that was stored in that exact device? Or do you switch device and complete the KYC on other device as the files that needed to be uploaded were on the other device? Do you happen to remember which device is this?