Outdoor sensors at cold winter

I’m using ConBee II with the latest FW, latest version of HA + latest version of deCONZ addon.
Everything worked perfectly until the current cold winter. My outdoor Tuya sensor (with two lithium AAA batteries) does not update both temperature and humidity if it is colder than exactly -20°C. I’ve tried to put outside one of my Aqara WSDCGQ11LM sensors - same problem. The last temp it has reported was -19,8°C. Both sensors has fresh batteries. I understand that these sensors are not meant for outdoor use, but I’ve at least seen screenshots of WSDCGQ11LM sensor reporting -24°C and lower (with original xiaomi hub and software if i’m not mistaken).
Can it be some deconz\conbe\phoscon limitation? I do not like that both sensors stop updating at exactly -20°C. Have you ever seen temps lower than -20°C using deconz\conbe\phoscon stack?

Could it be that the batteries don’t hold up to that temperature? I did some experiments with Alkaline batteries in the freezer and most of them broke down somewhere between -15°C and -18°C.

No. I’m using almost new lithium aaa batteries inside tuya sensor. They can work at -20 easily (tested with old 433mhz weather station sensor).