TCM - Turner Classic Movies issue with aspect ratio

I'm currently using the xfinity streaming app beta on my LG 55Nano81 2020 version TV. The issue I'm having is with channels 903 and 1755, the HD versions of Turner Classic Movies. On the beta app, the aspect ratio is incorrect for the films being shown. They are stretched to fit the screen, rather than the correct aspect ratio in which they were filmed. This issue isn't happening on these channels with an xfinity cable box, just on the beta app.