I found a homebrew Samurai class on dandwiki.com; which can be found at this link: https://www.dandwiki.com/wiki/Samurai_(5e_Class)#Fighting_Stance
At the time of asking this, Earth Stance allows you to use a two-handed weapons with one hand:
While you are in this stance, you have advantage on Strength checks made to grapple and can hold a two-handed weapon in one hand whilst grappling a creature. Additionally, on one attack per turn, you may use your bonus action to gain a bonus to your AC equal to your proficiency modifier if the attack hit. This bonus AC lasts until the start of your next turn. Also while in this stance your feet are planted firmly on the ground, doing this grants advantage on Strength saving throws and disadvantage on Dexterity saving throws.
Is the second attack made normally or at disadvantage?