Has the Split been recorded properly in Quicken? Note it should show as a Split in the transaction list (register), not as Shares added. Sometimes downloads from financial institutions are wrong in this regard.If you look at the price history for the security, does it reflect the correct price per share before and after the split?
It's good to know that your problem is resolved and that it was as simple as restarting Quicken. I have also had occasional situations where restarting cleared things up.There is also a way to force Quicken to recalculate investments as described herehttps://www.quicken.com/support/recalculate-investment-registerbut that appears to be much more drastic than simply restarting. I'm not sure what this does behind the scenes, but I would not want it converting all my sales to FIFO.