the main post loop query is controlled by WordPress so there has to a ‘custom function’ that is affecting the query. If you’re using a Child Theme then temporarily de-activate that ( activate Parent Theme ) to check if theres an issue.
If not its most likely a plugin as you post list has adverts inserted between the posts that may be a place to check.
first of all sir, i am not using any types of child theme on this Blog. and Apart from this, I have also checked by deactivating all the plugins one by one on the blog, I have also changed the ad placement, but my problem was not solved, please help me.