I have a Note 5 SMN920W8 and just joined Koodo. However, I can only access 3g network, not 4g LTE. Can anyone help?
According to willmyphonework.net, that submodel shoudl work for LTE with Koodo. Now, go to settings, more networks, mobile networks, network mode, and make sure one of the options for network mode selected includes LTE. Restart your phone. Maybe even pull out your sim card and back in. Will it still not show? Make sure that you're located in an area with LTE coverage. There aren't many places without LTE left, but just to be sure.
You might need to reset your APN settings. Do they match what you see here:
When using Service Mode/Network Setting (*#2263#), it should be set to:  Automatic [*} >  Automatic [*]. Selecting 'LTE' alone or 'All LTE' networks will not allow you to select other network modes when you go back into the Network mode selection menu. In Service Mode and after selecting Automatic, tap MORE. Tap 'Back' twice, then tap 'End'. This saves your network mode setting and should allow you to select the LTE/WCDMA/GSM (auto connect) option from the Network mode menu.