reversals of the eclipse depths, something already visible in Fig.7 at the lower parts of the fits.

In order to understand these changes we investigate in the next section the nature of the star facing the observer during the primary eclipse. This is usually named donor star in a $\beta$-Lyr type binary, because it transfer mass onto the “gainer” star through a gas stream flowing from its inner Lagrangian point.

On the system reddening, distance and donor star
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Since we do not have spectroscopic data for our object, we must rest in the photometry to further understand the system. Using the OGLE-IV photometry and the disentangled orbital light curve, we obtain a $V-I$ = 2.42 mag at the primary eclipse. The location of this DPV in the direction of the Galactic bulge causes that the light from this object is strongly reddened by unevenly distributed interstellar matter.

This object is located in the OGLE field BLG535, which is distant from the Galactic plane by slightly over 3 degrees. In this direction dust is distributed highly non-uniformly and reddening changes on a small angular scale. @2013ApJ...769...88N have estimated reddening using red clump stars located in the Galactic bulge, so reddening 