https://github.com/NordicSemiconductor/IOS-BLE-Library/blob/dbb8a255185add411a643d76b111825c27b3217d/Sources/iOS-BLE-Library/Peripheral/Peripheral.swift#L347 I don't know if it will work, but it may be better to compare *characteristic* instances, not UUIDs.
https://github.com/NordicSemiconductor/IOS-BLE-Library/blob/dbb8a255185add411a643d76b111825c27b3217d/Sources/iOS-BLE-Library/Peripheral/Peripheral.swift#L347
I don't know if it will work, but it may be better to compare characteristic instances, not UUIDs.