my TIKTOK has similar event.

hacker manage to login my tiktok account, there's no alert of saying new login detected on other device, even with 2FA ON, hacker manage to login.

hacker use my tiktok account to make purchase from a tiktok shop, which selling phone accessories cost 200-600 range.
I guess they use this method to cash out once the order fulfilled.

that event happen last week, today i check the manage device and surprisingly saw the hacker device logged in again..

what can i do ya? please advice sifu