I´m using the mentioned beacon since last Fall and till yesterday without issues.
Yesterday before starting a tour I switched it on and everything I got was a Bluetooth sign on the upper left corner and a battery sign on the upper right corner. No life signs otherwise.
Luckily I have a back-up beacon in the car and I could do the planned tour.

Back at home I tried everything i could think of including updating the SW and perform a factory reset (that "apparently" works), but nothing helped.
So I wrote to Pieps (I live in Austria) and they just instructed me to bring the device to a shop in order to start the warranty procedure.
They also confirmed upon asking that I cannot solve the problem by myself.
If I were on a multi day alpine touring trip and it happened one morning in the middle of it would be in the best case quite annoying.

Did anyone have such experience, even with the corresponding BD devices (LT?)

One more odd thing:
If I keep the Send/Search button pressed while switching on, the beacon come indeed alive and goes straight into the group-check mode.
After that, keeping the same button pressed for 3 secs the beacon starts sending as usual, but then I have no chance to switch into search mode.
In the user manual I found no mention of these behaviors.

Thanks