Homekit addon is throwing an unhandled promise reject warning with three eve sensors

Hi,
I am getting the following errors running the homekit addon with three Eve Window Sensors. Can anyone help please, as after this the only way to get the gateway to respond again is to restart using systemctl.

2019-06-02 18:17:17.531 INFO : homekit: Update triggered for: 5b:42:c9:a0:2a:45
2019-06-02 18:17:17.539 ERROR : homekit: (node:10324) UnhandledPromiseRejectionWarning: TypeError: Cannot read property ‘getCharacteristics’ of undefined
2019-06-02 18:17:17.541 ERROR : homekit: at readPromise.adapter.queueBLEOperation (/home/pi/.mozilla-iot/addons/homekit-adapter/lib/homekit-device.js:2929:26)
2019-06-02 18:17:17.542 ERROR : homekit: at currentBLEOperation.then (/home/pi/.mozilla-iot/addons/homekit-adapter/lib/homekit-adapter.js:52:9)
2019-06-02 18:17:17.544 ERROR : homekit: at
2019-06-02 18:17:17.545 ERROR : homekit: at process._tickCallback (internal/process/next_tick.js:189:7)
2019-06-02 18:17:17.547 ERROR : homekit: (node:10324) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 9)
2019-06-02 18:17:17.548 ERROR : homekit: (node:10324) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.