Thanks @gkalyan for you response.Yes I have tried restarted dispatcher.We are using CDN infront of dispatcher. Raised ticket to  to whitelist the "Link" header at the CDN level.But I am not understanding,if we hit direct publish url(not through dispatcher), do we still need to whitelist the "Link" H...

We have created a custom slingfilter for dam assetsWe are setting two custom header through this filter (for all dam assets as pdfs,jpg...)as below:1. X-Robots-Tag2. LinkIt seems like both headers are getting set through slingfilter (verifying via logs).But when we hit pdf url from direct publisher ...