Filtering for app game adverts

[Mimi-]

Morning. We are with RM internet and have their safety net and user based filtering on the desktops and a 'default' policy for ipads and any other devices that the children don't log into. The filtering system works well but I have a question about the apps and adverts they create. Generally, as a rule, we don't have apps that have pop up adverts (like the games you play and get extra coins if you watch an ad) But due to lock down the teachers are loving an app called Happy Colour. This looked fine, but I discovered that every 3 colouring sheets a video ad appears (so far mundane fashion ads). I have disabled the app as I can't guarantee what advert will pop up next but is anyone with RM who have managed to ban ads?