We replied Sweatwater few days before.
Actually our musician tested on below configuration and we cannot reproduce your iasue:
Mac OS: 10.14
Pro Tools First: 2018.7.0
Apple Bluetooth Software Version: 6.0.8f6
Here is the video instruction of Bluetooth midi connection of Xkey Air, just 8n case you want to check it again.
There was one user reported another issue, maybe it relates to your situation, please check below:
Fixed – I believe the issue is if you migrate your data from one mac to another – i.e. new computer – you must delete the old midi configuration and let it re-recognize theCME keyboard