the letters are flashing to fast
the whole animation stops when the letter are flashing
the animation is slow - 40 ms is a good start for frame duration when making gifs
40 ms:
I suggest opening a layers from 5 to 15 or more as separate images
adding a new text layer on all of them, now add an effect you like on all of them, but don't use the same strength of the effect, but increase it gradually from frame 5 to 10 and than decrease it till frame 15, now merge the layers and save them. Use hem to make the .gif, you will get a much better transition. Will post an example a bit later on.
btw I don't like the color choice, but thats a matter of taste