Polymarket lost my $578 deposit - Relay Hub auto-converted USDC to BNB without a

On March 24, 2026 I deposited 578 USDC from Kraken to my Polymarket wallet via Polygon network. Within 5 minutes, the Polymarket Relay Hub automatically processed my deposit and bridged it to BNB Chain, converting it to ~0.90 BNB and sending it to an address I cannot access. I never authorized any withdrawal. I never connected my wallet to any external site. I never even placed a single trade on Polymarket.
Timeline of events (all on March 24, 21:18-21:23 UTC):
- 21:18 - 578.15 USDC arrives at my wallet from Kraken bridge
- 21:19 - Polymarket Relay Hub converts USDC to USDC.e (Relay Call)
- 21:23 - Polymarket Relay Hub deposits 578.09 USDC.e to BNB Chain via their Fun.xyz bridge
After that, I was completely locked out of my account for almost 2 months. Both Google login AND magic link login failed with errors - even though my Google account works perfectly on every other app and website. The bug was on Polymarket's side, not mine. I only managed to log back in 2 days ago after their support intervened, but my balance still shows $0.
What Polymarket support has confirmed:
- My wallet is a legitimate 45-byte Magic Link proxy
- I have 0 trading activity on their platform
- The transaction was processed through their own infrastructure (Fun.xyz bridge)
- Their response: "the relay only executes signed requests" - implying my session was compromised
What I have verified:
- My Gmail has no suspicious sessions, all from my devices in Bilbao
- I never connected my wallet to any external dApp
- The login bug affected BOTH Google login AND magic link, on multiple devices and browsers
Key data:
- Wallet: 0xad7c39bA28a4b7C2B060d7615A2CC6F1BD86Ca5a
- Deposit TX (Polygon): 0x290832c585d3ac8ebe4c7931380bae134dba1d6bc1d91236c2dc5933dcc2123f
- BNB Bridge TX: 0xce2f7098125881a3414c0a6753c7737c78fb7bc7c091ba56653482cfd39c73de
- Destination on BNB: 0x0b5f474ad0e3f7ef629bd10dbf9e4a8fd60d9a48
Has anyone experienced this? Is there a known issue with the Magic Link proxy system that auto-bridges deposits? Any technical insight would be appreciated. I have all screenshots and full documentation.