Noticeable speed drop since G4AR switched to SA mode?

So it appears that my G4AR is connecting in SA mode now, as HINT no longer shows any LTE info when in use. Sadly, this seems to have done nothing besides cause a very noticeable drop in download speeds-- I've gone from 400-600 Mbps down and 40-60 up with ~18-25ms latency to a marginal reduction in latency (15-20ms), marginal increase in upload speeds (to 50-70 Mbps), and a halving or more of DL speeds (250-330Mbps).

The signal quality and strength has remained the same, so I'm guessing the G4AR does not support SA CA? Is there a way to force it back into NSA mode, or am I just straight up SOL?