There are a few reasons why your Instagram post may say it cannot be recognised:

Please ensure that your account is set to public. Since our platform automatically scans and retrieves information from Instagram, we ask that you please change your account settings to public for the posting of the photo. After submission and the task has been approved, you can change your account back to private and you will retain your points.

Double-check that if the task is asking for multiple hashtags that they are all included in the post. Hashtags must be included in the post caption, rather than the comments section, in order for the post to be recognised.

Please make sure that the post you are submitting for the task as evidence is a new post as the system may not pick it up if it is too old.