Issue:
Some user may find that sometimes two same text object (style, content, all the same) would display as two different shapes, as below pictures:
If you look carefully you will find that the below text object display rougher than the above text.
Cause:
The reason for this problem is because the rougher text is not on the XY flat. (Their Z-axis position is not zero)
And in principle, CAD software would only process those text which is on the XY flat and make them look smoother, for those text which is not on the XY flat, the software won't process because if it would take too much time.
Solution:
Change the Z-axis position of the selected text object to zero, problem solved.