Reasons for the reduction in Baidu's inclusion after the website move and solutions

Many webmasters will encounter such a situation: after moving their website, they find that the number of pages indexed by Baidu has decreased. Today, I saw a claim on a forum stating that Baidu uses its own DNS data, which is said to be updated only once a week. The reason for the reduced indexing after changing the IP address is that Baidu still checks the old IP. If the old IP cannot be accessed, then the number of indexed pages from that part will decrease. Therefore, when everyone transfers their data, they do not close the old space, but wait for some time before shutting it down, ensuring that Baidu can normally index the site at the old IP.