I have a carrier tail light, which was given free with my bike.
At first it was fine. I just noticed that it stopped working during a stop. I changed to fresh batteries but nothing happened. I really thought it was dead. After reaching my house, I tried it again after a few hours and it was working even with the old batteries.
I think it has something to do with the temperature in the room and outside. I use it flashing by the way.
If you came from a cold room then went out, there’s a chance that your tail light might act up a bit. perhaps this is due to the condensation of moisture.
This happens to me using my Cateye Auto/Reflex light coming from an office with A/C and the humid temperatures outside the light doesn’t work and the blinking mode was reset.
Initially I thought it was the weak stock battery that came with it but I later found out it’s about the cold batteries and warm weather.