Cloaking ads on Telegram is honestly very difficult because the system detects channel changes really fast. It is normal for them to review it again right after you change the content; it is almost automatic. Some people post clean content first to get the ad approved and then change it later, but this also increases the risk of getting banned in the long run. Right now, there does not seem to be a solid cloaking method. Maybe you can buy a little time by making softer transitions in the content, but there is no completely safe way.