This only happens when textures used for action menu has Mip Streaming enabled. Action menu textures should use highest mipmap quality when possible. Perhaps Texture2D.requestedMipmapLevel can help?
Attached two screenshots, one from Live and one from Beta (blurry)
Example avatar ID with this issue: avtr_8b5d44b2-5aec-4176-afc3-93ead7dd183f