Sometimes you may experience problems in the process of Ledger connection to Temple. To solve these issues, try the following:

• Untick the Ledger live checkbox in the Temple settings and try again.
• Check that you have the latest Ledger Nano update 
• Check that you don't have problems with a connection cable (try to connect to another wallet)

If you want to add multiple accounts from Ledger to Temple, follow this guide.