Yes, the LNBF has been incorrectly mounted 90 degrees out of rotation. Reference the skew "0" mark to the horizontal polarity, delete the current transponders then rescan. BUT.... being 90 degrees out of skew is not the cause of signal loss, The incorrect skew only creates transponder and channel lists with incorrect polarities displayed.
The Amiko STB Signal Quality readings were always a bit wonky. Does the V8 display SNR (or CNR) value for the Weigel transponder? If so, the V8 SNR readings to compare between the times of receiving and not receiving would be helpful. A SNR (or CNR) gives specific signal report vs an SQ reading that is just a manufacture's uncalibrated setting.
Also, the Weigel transponder 4180 H (DVBS2 FEC 5/6) requires a significantly better signal to decode than the Jewelry transponder 4140 H (DVBS FEC 3/4). FEC 5/6 means that 5 out of every 6 bits of data must be received to properly decode and display (83.33 %), The FEC 3/4 is more forgiving as 3 of 4 bits of data must be received to properly decode and display (75 %).
BTW... It is possible that the V8 satellite meter is simply capable of decoding the transport stream and display programming with a lower signal than the Amiko is capable of decoding. If this is the case, a different STB might provide a more sensitive tuner or better coding to decode poor signals.