Are you using the auto text resizing with -R or -RM on the text name?  That will auto size the text width only to fit as needed but won’t scale the text height.

If the text height is changing too then it is probably a corrupted text layer.  That happens no and then.  Try creating a new text layer from scratch.  Before deleting the old text layer you can also copy the layer style and apply it to the new text. Right click on the old text layer and select copy layer style. Then right click on the new text layer and select paste layer style.  Finally, delete the old text layer.  Then test the template again.

Let me know if it happens on the new text layer. If it does then post screenshots of the text as saved in the PSD and then after the auto text replacement. That way I can see how it is rescaling.