Hi @Mshaji ,
When you upload the image(asset) to AEM Cloud it kick starts the following process as shown in below image.
Now Make sure that
a) is there any post processing workflow configured?
b) Asset processing depends on the configuration in Processing Profiles.Check is there any custom profiles applied.Usually default configuration provides very basic rendition generation capability.Check is there any custom profiles applied with additional rendition generation capability.
Refer the below AEM Assets Cloud link to identify how to check whether any custom profile/custom workflow configured in your instance.https://experienceleague.adobe.com/en/docs/experience-manager-cloud-service/content/assets/manage/asset-microservices-configure-and-use
Hope this helps.
Regards,
Rajashankar.R