Incremental Refresh does not refresh fully the first time

[PshemekFLK]

My PBI report is using only sharepoint files as data source. 

I followed this video to set up an incremental refresh:

Incremental Refresh with SharePoint Files - YouTube

I managed to follow all the steps. I created Date/Time parameters (RangeStart = 3/20/2023 and RangeEnd = 3/21/2023) and filtered the Date/Time column on few fact tables. Query loaded quickly in PBI desktop (as expected since it's only one day of data). I managed to turn on the incremental refresh for each of the tables:

When I publish to service the initial refresh takes similar time to what it took before setting up an incremental refresh suggesting that it refreshes the full data of 6 years. However when I open the report it only shows the data of yesterday as if nothing refreshed but just the desktop version was published with the data of one day.

When I make another refresh it takes only few minutes as if the incremental refresh is working. I'm totally confused. Why would the first refresh after republishing not include all the data? Are the default values of parameters set up incorrectly:

Below is how RangeStart and RangeEnd are called out in PQ:

It seem that default parameters are not overwritten by incremental refresh for some reason.

[PshemekFLK]

I'm wondering if some of the subsequent steps in Power Query could cause the query folding to break. I'm filtering 3 tables with RangeStart and RangeEnd and then appeding them into one. Could this be a problem?

[ppm1]

Glad the video helped out. Seems like you got it working, but maybe you viewed the report before that initial refresh and just needed to refresh the browser to see the updated report. Also, you are correct that the initial refresh needs to process all the files/partitions, but the later ones should be much faster.

Pat

[PshemekFLK]

The video is great and very easy to follow and I watched it carefully few times to see if I didn't miss anything. I refreshed the browser page multiple times and I'm 100% sure it was after the refresh completed. I tried republishing couple of times - still the parameters are not overwritten and report shows only one day of data as per default parameters.