It tiles if you plug image alpha into surface brick opacity, not material brick opacity. Well, sort off, there was image at the middle and tiled ones together, like its displaying both tiled and non tiled image.
But you can ignore image alpha. Plug in image color into both diffuse and opacity color of material brick and it should work with alpha channel .png. Besides, if you put .png with alpha channel into opacity strength channel of the DAZ studio default shader (surface) it will work for tiling and opacity.
Edit: Hmm, it looks like alpha channel from.png I used was treated in DS as black color. If i put it in diffuse color, what is invisible renders black, which in opacity strength, ofc, renders invisible.