ESP doesn't wake anymore

[MoisAlexander]

Hi,
ich have 4 doorsensors in use. I use 3.2 V batteries and which have to be charged every few month. The voltage check does not work till now, I think I have to change the config. But that's not the problem.
My sensors worked since month without any problems. A few weeks ago one of my sensors stopped working an so I changed the the battery. But that was not the solution. It still didn't work. Next I flashed the ESP again and now it works. But it send's only one time after restart and then it goes sleeping and didn´t wake.
Because my sensors are flashed with a slightly modified code I tried the original one, but that does not work too.
I thought maybe the ESP is broken and flashed an new one, same problem here.
A week after the first sensors a second stopped working, I flashed it, same problem.

Now I don't know what to do. I made everything like a few month ago. The only difference is my notebook os, but I cannot imagine that can be the problem.

I hope someone has an idea.

Thanks
Alex