IBS-P02B Pool Thermometer Bluetooth issue

Hi all.

I have an IBS-P02B in my swimming pool. For the most part it works as expected, however the bluetooth has just stopped workking.

I am unable to connect to it via either the engbird, or inkbird apps, on multiple phones, nor via an esp32.
I have tried reseating batteries, changing batteries etc.

The bluetooth icon is still showing on the unit, and the display is showing the correct temperature.

This is the second time it has happened. Previously it was only a few months old so was replaced by the place of purchase.

Surely it should last longer than 12 months ?

Hello,
Please check if there is water inside the IBS-P02B?
Please make sure the Bluetooth and location function of your mobile phone is on, please make sure your mobile phone is not connected to other Bluetooth devices. If you use INKBIRD APP to connect, please note that the model selected for connection is ‘IBS-THS’. Please do not connect the Bluetooth signal of IBS-P02B directly in the Bluetooth settings of your mobile phone.
IBS-P02B can record 30000 data points, if the limit is exceeded, the historical data will be overwritten.

There is definitely no water inside.
I have tried multiple devices which have all worked previously.

I cannot detect it in either the engbird or the inkbird app.

Other than bluetooth connectivity, the device itself is working. The display has no fogging etc, and it is showing the correct temperature on the screen.