OK, I reproduced it. The text filter is overwriting the alpha channel on its output.
The workaround is to create a V3, put a transparent color clip on V3 (File > Open Other > Color), and add the Text filter to the transparent color clip.
OK, I reproduced it. The text filter is overwriting the alpha channel on its output.
The workaround is to create a V3, put a transparent color clip on V3 (File > Open Other > Color), and add the Text filter to the transparent color clip.