monthly table with applied steps append into a static?

Hello there...

Ive set up a process that was in an access database into powerbi - yes i know, painful. 

basically every month, I will import a spreadsheet in, create some applied steps to clean it up, and link in current validations based on the max date in there (this is in a seperate table linking to an access database that i do not have the right to change) so in the end i have a validated month end table.
I need this to be static, not linked to validations in any way, and be able to repeat the process every month so i have a master static table of monthly validated patients.

My idea, was to append this into a master table (I made a static enter data version), and for the next month just replace the above spreadsheet process to next months downloaded file just in the source - so all that linking and cleaning was already done, and just append onto it.  But im getting cyclic reference errors?

I didnt want to import and keep each monthly file in there along with replicated all the applied steps, I thought i could just keep appending the process in one static table.

have i gone about this the wrong way? is there a better way
appreciate your advice
liz