Sending the test campaign with the "Skip Wait Times" option enabled:
If you have selected the "Skip Wait Times" option, all templates will be sent simultaneously, which may result in the messages not being sent in the intended order.
Sending the test campaign from a specific template, without checking the "Skip Wait Times" option:
In this case, the most common error is that a text message may arrive before a message containing media. This is usually due to the fact that the media takes longer to load.
As a result, META automatically sends the next message before the media is fully loaded.
To avoid this, make sure to increase the wait time between the template containing media and the next message. This will allow META to avoid sending the next message too quickly, giving time for the media to be fully downloaded.