Unable to get a managed property (a sharepoint library choice column) appear in pnp search filters

Hello Everyone,

I am unable to figure a solution for issue I am facing with a managed property in SPO. 

I have a Document library column "Department" which is a choice field (With some values such as HR, finance, etc). I have a PNP search page in the site, where I have configured a PNP Search bpx, PNP Search results & PNP Search filters webparts.

The pnp search results show data from a Document Library. Also the PNP search filter webpart is showing a couple of fields such as "file type" and "content type". However I am unable to get the "Department" appear as a filter in the PNP Search filters.

Here is the library column which I am trying to get to show in pnp search filters

I see that the name of this column internally is this : 

In SharePoint Admin centre, I tried two different things : 

1. I used an existing "Refinable string" (refinablestring01) which was not mapped to anything. I mapped it to the crawled properties. I wasnt sure which crawled property is the exact column, so I mapped it to 2 or 3 crawled properties that are for department as below.

The "refinable" property is set a "Yes-active" for the above property.

2. I also tried creating a new managed property and tried mapping it to the same crawled properties as above. 

But even after a few days, I am still unable to get the column to show up in PNP Search filters. 

I can see the "Refinablestring01" in the search results/filters as below

I also see "Refinablestring01" in the pnp search filter webpart properties dropdown

After publishing page, I still can't see "Department" as a PNP Search filter.  

Any suggestions on what am I missing? Why does the "Department" column from the library, not show up in pnp search filters?