I can not see my custom stickers in whatsapp but they are visible in the stickers app itself. What could be causing this? I made sure they are under 100kb each, are 512x512 sized and that they are webp files. The naming in the json is also correct.
What do you mean by "can not see my custom stickers in whatsapp"? Are you not able to import them or do they not show in the picker?
They do not show in the picker
Importing them works and they do show in the app where you import them from
I have exactly the same problem.
I have too
After a dozen hours of 'try-again's I've managed to solve this for me. When converting from png to webp, be careful not to save any metadata. If you're using the same photoshop plugin as I am ( https://github.com/fnordware/AdobeWebM#download ), then you must have unchecked the "Save Metadata" box.

Hope this helps.
I have this issue too
I found the reason for this. Working solution here:
https://github.com/WhatsApp/stickers/issues/167#issuecomment-437684615
Please put a thumbs up ( :+1: ) if the answer worked for you. I'd highly appreciate it :)
Most helpful comment
After a dozen hours of 'try-again's I've managed to solve this for me. When converting from png to webp, be careful not to save any metadata. If you're using the same photoshop plugin as I am ( https://github.com/fnordware/AdobeWebM#download ), then you must have unchecked the "Save Metadata" box.

Hope this helps.