Environmental and server load factors can mean that there is a delay in data reaching Financials and often it will appear after a time.
Having confirmed that the transaction is neither posted, nor batched, please check the datahub information from the Utilities menu in the System module.
Data received and posted will show as a status of 1, and so anything not processed will have a different value (eg 4).
Identify any anomalies and check the message text. This can be copied into a text file and often problems can be identified by comparing it to a successful posting.
Some common reasons are:
No Detail information - the text will contain "DetailLines":[] with nothing between the square brackets.
You may need to raise this with the users processing the imported data in the source application.
If you require assistance from either that, or the Financials Support team, please raise a new case online, providing as much detail relating to the missing transaction as possible.