... it has no problem receiving my Baofeng on UHF.
Can you tune your Baofeng to any UHF channels that got activity and then compare to the SDS100 on the same frequency? It could be that you are too far away from the transmitter or in a bad spot. If you have several other receivers/scanners you probably will know how your conditions are.
I hear almost nothing if I use my scanners own antenna. I need to use roof mounted antennas and the biggest I can find to be able to hear something.
If you have confirmed that your other receivers can receive a signal then its time to experiment with the different filter settings and IFX in the SDS100.
/Ubbe