Both Corvus BC-1 and BC-2 are not alive as far as we know. They were pronounced dead shortly after insertion, 2.5 years ago.
“Fregat thruster damaged some of the CubeSats”
Scroll down to July on this source page.
According to the attached PDF, just retrieved from this URL, root issue was hydrazine leak in first stage of launch vehicle.
Page 10, Failure source reference row # 11
“14-Jul-17 Soyuz 2.1a/Fregat M Corvus BC 1,2”
Page 26, Table 3.1 Reference row # 11
“Later found to be fault in Fregat’s first stage engine-spill of hydrazine.”
However BC-3v2 and BC-4 are alive as far as we know.