My 30shrs & 100 shrs of GLV were combined at 10.85/share but brkr left the cost basis empty. When I fill in the cost basis it all appeared as loss. Shld I leave it blank?

Turbo tax keeps making me fill in the cost basis and if I do it shows I lost all capital when actually have a gain $$. Should I just follow the way Charles Schwab filled up the form and ignore the warnings from TurboTax?