The Data On does not change the IC-9700 on the Sub band. It is working on the Main band.
Radio Model: IC-9700
Connectivity (USB/Ethernet/Wifi/Other): Ethernet
Operating System: Win 10
wfview version (press “About”): 2.03
Checked the wfview manual (Y/N): Y
Checked the wfview FAQ (Y/N): Y
Tried to google it (Y/N/NA): Y
What I did: Set Data Mode On in Sub-Band, for example LSB Mode Data ON
Unfortunately that is due to the way that the protocol on the 9700 works. Unlike other main/sub radios (like the IC7610/785x) there is very limited scope to modify the sub band.
This is something that we should be able to resolve, but as a workaround, you can use the M<>S button, change the settings and then M<>S again to swap them back. Not ideal, but it should work for now.
Even Icom’s own RS-BA1 software only supports the main band remotely on the IC-9700. If the sub band is on when you connect the software it gets turned off. I remote my IC-9700 full time so I have just gotten used to only having one VFO available when I use their software. I have complained to Icom directly but I don’t think they will be releasing a firmware update anytime soon to make the sub band fully functional via remote.