All images have signal finder, no need to install any other plugins. Please post a screenshot showing Signal finder with tuner B activated and tuned to 11426 horizontal. Signal finder will be in Tuners and Scanning or Reception depending on image. Make sure you select correct:
Tuner, B in your case
Frequency, 11426 for Freesat
Polarisation, Horizontal for Freesat.
Horizontal is different to Vertical
When you did a full rescan, are you referring to scanning using ABM plugin or scanning function in Enigma2? If scanning function in Enigma2, how many services did you find?
Wild guess: Are you using a wideband LNB for Sky Q? Those LNBs only have two connections. Universal Sky LNBs usually have 4 or 8 connections.