Yellow alpha

[CaptainNichols]

I don't know where to write this to am commenting this here, am using your website https://www.piskelapp.com/ to make characters for my python school project, i have this issue where my first frames alpha(invisible color) is yellow instead of alpha, ive noticed this happening in all gifs edited via your site. This might be a issue with me but i would really appreciate some help/for the bug to be fixed.

p.s If i open it in the browser the background appears alpha but once downloaded the first frame turns yellow

If you are reading this and fix the issue/ help me with it id appreciate it a lot thank you for your time <3