Adamgell,   Through testing we can confirm what you're seeing is correct, it has been submitted, I am not certain when/if it will be addressed, but maybe in its upcoming releases.   Thank you for taking the time to bring this to our attention.   
Hi, The dropdown when adding a device manually only loads ~26 items. We have over 30 credentials loaded and its growing.  I see in the API I can set an offset and get the information I need to load devices via the API but I can't get that working either. 
Device Credentials not fully populating on new device add