To find out the exact reason, we recommend to contact your manager.
Before doing this, check according to the list:
There is money on the balance.
The ad passed moderation.
You have launched ad display.
Your campaign and ad limits have not been exceeded.
If you have time targeting, make sure that the problem occurred during the time slot when your ad had to be displayed.
The bid/сtr corresponds to the average indicators of your targeting, you can check this in your personal account, the “network volumes” section.