I’m new here so take my advice with pinch of salt….
Are you using AE Text as a 3d layer with a light casting your shadows?
If you’re not and you are using the drop shadow layer style or plug in then turn that of, make your text a 3d layer and apply a light to the comp making sure the ‘cast shadows’ checkbox is ticked in the light options. Make sure your ‘solid’ that your wanting the shadow to fall on is also a 3d layer and make sure it has the ‘accept shadows’ box in its ‘materials options’ ticked or saying yes (can’t remember which) the shadow will animate with the rotation of the text on the background layer. Also make sure the text layer has ‘cast shadows’ ticked in its ‘materials options’ as well..
If you are doing this already then I’m stumped…
Y