Captions not centering

Hey! I've been having issues with captions not centering at the bottom of the screen. The text alignment options in the captions panel don't enact any change either, wether the blocks and words are highlighted or not. Could it be because I am captioning a 1080p portrait video as oposed to landscape? It's almost as if the padding on the left is cemented in. Is there not a way for Premiere to automatically detect the frame size and center/drop lines accordingly (just like Youtube does)? Thanks for the help!