Hi @cgarib_tei
The action "post and adaptive card and wait for a response", cannot be used with the "Teams adaptive card" from "Create an Approval" outputs.
You have to use one of the 'Post an adaptive card' actions on the Teams connector that does not wait followed by the 'Wait for an approval', anyway it should give you an error so I supposed that you are not using the "Teams adaptive card", in that scenario the problem could be that the users that you send the "Approval" has not answered the email.
If you can share how you edit your flow, it would be better to give you a more accurate response.
Hope this helps.
Best regards.
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.