Lost in translation. Data mysteriously not able to be Symbologized.

[BrianDeis]

I recently joined some ACS data to a TIGER line Shapefile and the data was imported as a .csv from excel, all was fine.  I made my layout and exported it with a graduated symbology, no problems.

I go back to edit something as it was signed improperly, lo and behold, all the percentage data no longer is recognized by the symbology tool.  Can't even see it to be selected.

I'm certain it was there the first time a made the map.  Nothing changed.  No files lost.  No field attribute changes.  Just will not populate the drop-down for the field which I joined.

I have gone in and created a new field manually formatted as float, percentage, manually entered the data, but that takes forever for 5 counties of data.

What happened?  How do I fix this?  Is there a tool to just copy all the percentage data from one field to another without manually entering it?

Thanks.

[MichaelVolz]

Is this work being done in Pro?

Have you tried a similar workflow in ArcMap?

If data was in shapefile format can you keep it in that format?  If the ACS data was in excel format, can you convert that into a table in desktop and then perform the join so you avoid the csv format.

There are posts about bringing csv data into Pro where there are problems and its been advised from others to convert csv into a table in Pro and then work with that formst.

[KoryKramer]

And to answer the question  

Is there a tool to just copy all the percentage data from one field to another without manually entering it?

Use Calculate Field to calculate field x to equal field y: https://pro.arcgis.com/en/pro-app/tool-reference/data-management/calculate-field.htm