png2webp with purple fringing

[s01o]

a1.png (204.06 KiB) Viewed 29890 times

a1.png
use any setting to webp
with purple fringing like 20210326234009.png

20210326234009.png (103.03 KiB) Viewed 29890 times

But it's no purple fringing with xnview(100quality)

Before this picture is transparent
Its background is purple
Used this software to replace purple to transparent
I think this may be the reason for the purple fringing after conversion.
When there is any compression, webp will appear purple fringing
The difference is that xnview 100quality compression does not appear purple fringing
ImBatch 100quality compression still has purple fringing

Translated from google
Please forgive if it is difficult to understand

[Max]

Can you please try this "work-in-progress" build? Use"Lossless" option for webp.
Looks like we fixed the problem. Can you confirm?

[s01o]

Perfect,extremely thank you.
好人一生平安.