When trading on multiple exchanges like CashApp, Bitstamp and Coinbase, 1099-K and 1099-B forms are double taxing, since gain/loss is calculated on Koinly. What to do?

[intuit]

Koinly has all my Coinbase, CashApp, and Bitstamp transactions imported and is calculating my gain/loss for the year at a couple of hundred dollars, but then Bitstamp and CashApp are sending forms where the cost basis isn't correct and the gains are each more than the total from Koinly including all three exchanges. Does that mean I'm supposed to remove their transactions from my Koinly calculations and just be forced to accept the way Bitstamp and CashApp are calculating my gain/loss, and only calculate my own gain/loss for the Coinbase transactions?

[JamesG1]

Are you seeing transactions being reported twice?  

If so, you may need to review your transactions to:

• Correct cost basis for transactions that are missing a cost basis or reporting an incorrect cost basis, and
• Remove duplicate transactions.

If you have imported your transactions into TurboTax Premium Online, transactions may be reviewed or corrected within the software.

Check the box to the left of the transaction to invoke Bulk Ignore / Bulk Edit functions.  The Search box and Search funnel may be used to review like transactions.  The pencil to the right may be used to correct transactions.

[intuit]

Not seeing transactions twice. Getting 1099-K from Bitstamp where the gain is the same as the total sale which seems like they’re assigning a cost basis of zero. CashApp sent a 1099-B where they appear to have pulled a cost basis from thin air so the gain is also high there. but the transactions that Bitstamp and CashApp are reporting are also reported on my gain/loss report from Koinly and have a higher cost basis. I feel like I’m being double taxed and shouldn’t need to include the 1099-K and -B