Someone in this thread has no idea how a rohloff operates clearly judging by the post :s
Is it iust giving no drive connection at all or is it skipping ?
Has it got a click box ? ( ive only worked on my own which is clickbox)
Remove the click box and go through the gears 1 x 1 using an 8mm spanner to turn at the hub
Ride the bike in between and determine if it works that way
If it works then is likely a cable/clickbox or shifter issue – next step would be to check the clickbox set up as first time i did mine it took some fiddling to get it all right
If it doesnt work at the hub with the 8mm spanner id suggest there may be water content in your oil perhaps freezing up and stopping the plannetary gears engaging
Worth bringing it in the heat for a while and performing a full drain , cleaning oil , new oil service ? Could possibly also be over full of oil and once it thins out with the heat of riding it allows the hub internals to move freely