QGIS downsample then upsample raster

I’m trying to downsample a raster then upsample it again.

I am using the gdalwarp function in QGIS.

When downsampling the raster looks OK in the front end, I set the cell size to 10x the original raster.

When upsampling back to the original cell size using the downsampled raster the original data seems to be preserved and I end up back at the original raster. What I’m expecting to happen is that I see blocks of 10×10 cells all with the same value (same as the downsampled raster).

Does QGIS preserve the original cell values? Is there a way to perform this operation?

Thanks