I did a test, each time I call the method, the font become whiter and whiter … If I apply it 5 times for example, it looks the same way as in Flash … So I have a work around, but not really optimized …
Last openFL version fixed my issue, did you test it ?
I had nearly the same issue, first popup opened had the correct behavior, and then, each time I opened it, the textfield was messed up.
There should be no longer a problem with updating text property in a TextField with a filter applied on it. Have you checked with the latest release or development builds of OpenFL?