Could just be the light, could not be working.
EASY to verify.
Accelerate at WOT from 0 to around 45-50 with economy not pushed. Record max RPM in each gear.
Engage economy mode and do the same.
If max RPM is the same in power and economy mode, it is not programmed properly (never seen that on an RV, but certainly could happen).
If max RPM in each gear is lower in economy mode, it is working.
John could tell you about the light and may be of assistance if it is not programmed for economy mode:
https://www.transmissioninstruments.com/