I have the same issue. Can't get the 4x1 widget back after accidentally deleting it. All I get is an ugly 4x2, that is different from the real 4x2.
Poweramp 2.0.10 build 588, Poweramp Full version unlocker 2 build 26
Sony Xperia ZX1 Compact g8441
Android 8.0.0, kernel 4.4.78, version 47.1.A.12.270