I have exactly same issue in my Form 1099 provided by Robinhood. I also had sold all my stocks last year and didn't purchase same or any similar stock in 30 days of sale.
In my case, I had an actual loss of $10K, Which is calculated same by Robinhood (by calculating using my original cost-basis), but at the same time it showed me the Wash Sale loss disallowed as $8K. That essentially means, I can only show a loss of $2K, instead of $10K actual loss.
I reached out to Robinhood with this problem and they ask me to send the details. I'll share them the transaction details and will see what they respond.
I'll be interested to know if you also get any answer from them or any other information or details from any other means on how to resolve this issue.
