Rudy noticed that these sensors were down.  After resetting power on both:

200m: TRH30 9.49 65.31 8 0 1238 129 26\r\n

(fan has low current)

300m: TRH16 -40.14 0.00 9 0 0 0 30\r\n

(sensor is essentially dead)

Both sensors are going through frequent reset cycles as well.  I don't know if we even have replacement sensors ready to go.  (Or whether we should bother with fixing this with one week left in the project, officially.)