When this happens if you view the source of the page (right click) and then look are the image tags populated or the src fields empty?
If they all have image urls then it’s unlikely to be the lazyloading in javascript / front end. If they look fine then my suggestion would be to run without lazyload for a bit to see if it solves the issue then you know js is failing (e.g. just replace data-src with src and remove the lazyload class.
If they look empty / weird then my guess would be an issue with the Umbraco cache. This can be caused by having multiple web apps pointing at the same DB, scaling / incorrect load balancing setup or something weird in the setup of hosting. If you’re finding it’s fine following a release then you see errors in the logs after a while I’d suspect it’s something along these lines. Do you use separate DBs for dev / live / uat etc?
Do you have both packages to correctly use the azure media with a cache?
Umbraco.StorageProviders.AzureBlob
Umbraco.StorageProviders.AzureBlob.ImageSharp
Luuk pointed me in this direction which has solved some issues I had in a v13 project that was upgraded from v10 and I’d not added this extra package….
My only other thought is you’ve posted the log which says sending image with the request uri https://new.contoso.com/ as the domain - do you have the UmbracoApplicationUrl correctly set in the appsettings.json seen Azure do weird things with routing if it starts up and is hit on one url and then serves on a different one.
HTH
Steve