Unfortunately, Hubitat integration to Amazon Echo Skill does not include water leak sensors. Search this forum for "leak sensor Alexa", a possible workaround is to make a virtual contact sensor exposed to Alexa, then sync the contact sensor open/close states with the water leak sensor 'wet' / 'dry' states using RM5 rule in Hubitat.
Battery level reporting for the leak sensors is very important in my opinion, this is what determines whether the sensor is operational and online to HE or not ... If the sensor does not send any battery reports in the last 12 hours period, the driver will send 'not present' event and the battery level will be forcibly set to 0 - this is the way I use it with the Device Activity Chek and Device Watchdog apps to monitor the health of the sensors...
The easiest way to troubleshoot the missing battery level reporting is to pair your sensor again to HE, close to the hub. Can you also post the identification information from the device web page 'Data' section? ( model, manufacturer, application )