I have a very strange issue after converting a Catalyst 9300 to a 9300-M (non native beta). During the conversion the switches never contacted the Dashboard and had a management IP address of 198.18.0.0/28 range. I could see this from a connected router cdp neighbor details. I couldn't manage via the front ports on this range, or use the console port so ended up factory resetting by holding down the mode button for 21s. When the switches booted back up they successfully got DHCP address on private range, but then rebooted after a period of time, am guessing after downloading firmware, and now back to a management IP address within 198.18.0.0/28 and unable to reach the Dashboard.
Anyone any thoughts on this or experienced this before? I know this range is used for local device management on 9300 switches. But what I don't understand is why when DHCP is available it is defaulting to this as a management IP.