In brief explanation, even if you use the same NEM address, the generation method of DeligateAccount differs between NCC and NanoWallet. For this reason, formal information will not be displayed on the NanoWallet screen.
When switching from NCC to NanoWallet, please set Deligate Account and Harvesting in NCC. Please disregard the display in NanoWallet.
There is also a way to say, NCC is not offered at the latest version now.
If there are still environments where NCC can start up, please Deavtive the Deligated account at NCC. (It will take about 6 hours.)
Then, activate the Deligated account (Remote Account) from NanoWallet. (This will take about 6 hours.)
When it becomes completely active, you can freely set Harvesting from NanoWallet.
If you do not have a working NCC, I think there is a “Use Custom Public key” on the left side page of NanoWallet.
You can use it to deactivate DeligateAccount Activated at NCC.
Check it and enter the public key of your DeligateAccout (created by NCC, not what is displayed in the NanoWallet).
Then select Deactive on the left side page and do Deactivate.
After 6 hours your Deligate Account (Remote Account) will disappear, so please use NanoWallet from here and set Remote Account to Active.
After 6 hours, you can set Harvesting as well.