Upper panel: constant period decrease observed in the discovered system. Two points from OGLE-III are averaged over the years 2004–2006 and 2007–2009, while nine points from OGLE-IV are averaged over each year from 2010 to 2018, separately. Lower panel: combination of phased I-band light curves from OGLE-IV seasons 2010–2018 together with the best fit (red line). Each light curve was cleaned from outbursts and outlying points.