What you could do is create a manual Send (withdrawal) transaction for the amount you sent to be locked, then tag it as ‘Sent to Pool’.
This tells Koinly that even though you sent them to be locked, you still own them but they’re not in your possession at the moment.
Likewise, when you unlock them, you would add a Deposit back into your wallet and tag it as ‘Received from Pool’ to tell Koinly they’re in your wallet again.