Have to dive into control panel each time to match converter sample rate

This doesn't seem normal.
I have to open control panel to get CbB to change sample rate each time I boot up and load in 
the DAW.
Am using a Motu 2408mkIII and in the preferences have selected 88,2khz sample rate at 32bit length but
the default seems to be 44.1khz but each time but corrects opening the ASIO menu and closing.
Any way to keep the preference at opening the DAW.
Cheers 

cheers bro, tried it but still an issue. Strange! Once CbB opened if I open and close preferences devices it corrects.

It definitely sounds like you've got Windows set to use your MOTU as it's default sound device, and it's trying to reset it to whatever sample rate it wants to and causing you issues.
 
If you've got a sound device on your motherboard, consider making this your default sound device for windows so that CbB has complete control over your MOTU.
 

msmcleod is making a good point not to take lightly. The default device is controlled by Windows, not you, so with an audio interface that handshakes properly, every app you open could task Windows to change it.

My onboard Realtek is default for this reason. With exclusive rights given, Windows can even lock your AI out on you. The non-default devices just show up when powered on and apps that need them can find them, but Windows won't let every app access them.

Every app you run that can produce sound can request Windows reassign your AI settings when it it the default (i.e., Windows managed) device.

must be a to me only issue.

Windows requires you to explicitly select the default audio device (can be a PITA until you know this). Basically, you need to bring multiple units online and set one as default. The "explicit" means that even if you are lucky and the one you want to be default is already, you need to assign something else, then go back and assign the one you want. You should only have to do this one time, but I found out that a new device will get assigned by Windows when installed (installed a new monitor that had sound, so had to do this again).
 
In the case of an AI for DAW use only, both the AI and Realtek need to be shown (I disable everything else that ever shows up there). Even if the Realtek is default, set the AI to default, then set the Realtek to default. The down-side is this requires another set of speakers (or you will not hear anything else), but the upside is that Windows should only see the AI as "online/offline" and allow a DAW to use it without interference.
 
Another item of note, is I uncheck the "Exclusive Mode" options at the bottom of the Advanced tab when you select a device and then the Properties button. When those are enabled, Windows can lock you out by the first application that sends sound to Windows. Most DAWs have a similar setting, which I also leave unchecked.
 
The only time I use my AI as the Windows default is for internal loopback, but the DAW is already up and online before I make that switch, and I switch it back when finished.