Robinhood’s SLV Put Assignment Basis Method Differs From Fidelity - Creating Artificial Gain

I got assigned on SLV puts at two different brokers, and the cost basis treatment doesn’t match. Trying to understand what’s going on **Robinhood case** * Sold 2x SLV $85 puts, collected $4.08 credit ($816 total). * Assigned 200 shares (debit $17,000). I expected cost basis to be: $85.00 − $4.08 = **$80.92/share**. Instead, Robinhood shows my SLV average price as **$70.05/share** (total basis $14,010). Robinhood support says SLV options are “Section 1256” and that when assigned they use an option “fair market value” (FMV) on assignment day and set share basis = **strike − FMV**. They claim FMV was $29.90, and that’s why $17,000 − $2,990 = $14,010. So instead of strike − premium received, they’re doing strike − FMV. **Fidelity case (different strike)** * Sold 2x SLV $92 puts, collected $2.79 credit. * Assigned 200 shares. * Fidelity shows average cost basis **$89.21/share**, which equals $92.00 − $2.79 (plus a tiny fee). So Fidelity is using “strike − premium received,” not “strike − FMV". **My Issue:** Robinhood’s method appears to: * Realize Section 1256 gain via mark-to-market * Lower my stock basis significantly * Make it look like I have a large embedded gain in the shares Economically, I’m not up - I’m actually at a loss relative to my intended basis. Has anyone dealt with this for SLV (or other 1256 ETF options)? Is this actually correct treatment under 1256 rules? How should I handle this from a tax/reporting standpoint? Would appreciate insight from anyone who’s navigated this.