@anuj27   I tried to replicate the issue and please find my observations on this.

1. When you add an image in the Topic,  it generates a URL link. 

2. This image is created as a record in Images table [db_image_list]. 

3. Kindly check if the images are available in that table. If so, validate if the sys IDs are same and republish the topic and check. 

Optional reference : https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0744449

Please mark this as helpful and accept it as a solution if this resolves your query.

Thanks,

Sujatha V.M.