may have the wrong settings selected. click on deck details then switch deck settings from 'standard' to 'traditional standard'. deck details can be accessed from the bar with the graph that indicates deck curve on the mid left side of the screen.
if its a best of one game you could maybe just clone the deck and then delete the additional cards in the sideboard that aren't useable in best of one.
would like to add i don't play against friends so take what i say with a grain of salt
may have the wrong settings selected. click on deck details then switch deck settings from 'standard' to 'traditional standard'. deck details can be accessed from the bar with the graph that indicates deck curve on the mid left side of the screen.
if its a best of one game you could maybe just clone the deck and then delete the additional cards in the sideboard that aren't useable in best of one.
would like to add i don't play against friends so take what i say with a grain of salt