Network Signal Guru pulls data from the Modem, and by doing so requires root, prior to the release of Oxygen OS 13 on the 9 Series, only Network Signal Guru could see you being connected to N77, post Oxygen OS 13 launch for the 9 Series, NSG, CellMapper, and other similar apps can see which 5G band you're connected to, this is because before OnePlus hadn't enabled broadcasting for 5G, now they do, OnePlus probably hasn't enabled broadcasting for 5G on the 10 Pro, or LTE Discovery can't see 5G data on OnePlus phones, if you root and use NSG it will show which 5G band you're connected to, alternatively, try CellMapper first.
Don't worry, that is real N77, the 5G UW icon is only whitelisted at the system_ui.apk for N77, N78 (I assume, hasn't launched yet), N260, and N261 only (only 9 Pro, and Verizon 8 5G UW), on my OnePlus 9 Pro, LTE discovery doesn't show N77 either, CellMapper on the other hand does, try it on your 10 Pro, it does not require root.
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