There could be several possibilities to this. My guess is that you have an extract that sits on the server that you are updating with refreshes/appending as an admin. And then you have workbooks that are connected to this via a tableau data source or even an extract.
I think that you are updating the data source but these workbooks are not connected live to the datasource so they have a snapshot from time t and you are updating at time t+1. They do not have this latest update.
You can have your tableau workbooks link to datasources on the server with a live connection or schedule them to refresh in a similar pattern to yours. IF you update at 6:00 AM then have them draw from the server hosted data source at 6:30 AM.
But this is one guess and there can be several possibilities. I would suggest you provide..
Is there a Server hosted datasource?
What are the workbooks connecting too?
What type of database/flat files?
Are you using .tds, .tdsx, .tde or a live connnection straight to database - both on server and from the workbooks?
Hopefully this starts you down the right path.
To answer your questions.
We do not have Tableau Server. My company rents space from Tableau and the space appears to be hosted by Amazon.
My workbook (.twbx file) is connecting to a TXT file. Like I initially stated, I am continually appending data to my main TXT file which then feeds into my report.
I don't know if you I am using a .tds, .tdsx, .tde - as far as I understood, I am using a TWBX file which holds the TXT extract in it. I don't know if that is correct?
That screenshot looks like it is from Tableau Server, it may be Tableau Online. Both of these are platforms designed to allow you to share a workbooks with a multitude of users. The difference primarily rests in who controls the actual server. In this case Tableau Server isn't a physical machine its a piece of software. But it usually sits on a physical or virtual machine by itself (the latter in this case it seems). Because you rent space from Tableau you should be able to reach out to your rep with that organisation to get an answer.
If your TWBX (packaged tableau workboook) is your workbook then this actually contains a .TWB (tableau workbook) and a .TDE (Tableau Data Extract). I am unsure how you are getting new information into your underlying .TXT file and then appending but that's not the major issue or concern here. You may wish to host this .TDE on your Server/Online and when you do so change your workbook to be a live connection to this extract that's now hosted on the server.
This way when you update the .TDE by appending data from the .txt file the .TDE Will contain all the data and then the individual workbooks will be connected to this new data live. If a user is logged on for several hours and you make an update in the middle of this, they will still have to refresh. However if they log in afterwards then they will see the updated version of your data.
Again there are possibly a lot of factors at play here so I would reach our to your internal admin or to your tableau account rep who may be able to provide these answers more readily. My organisation can do this as well but the issue being of course we do not access to your system, an NDA, nor a Statement of Work / Contract signed with you.
Hopefully this helps resolve the issue or at leasts gets you to the people who can answer them.