I don’t have any experience with Dexcom myself, but I suspect your transmitter is close to failure. The resistance is well above 1000. According to @docslotnick, transmitters die when the resistance is around 1000. He reported his experiences with the life span of Dexcom transmitters in this topic: How Long Does a G5 Transmitter REALLY Last? **UPDATE-Transmitter Died** UPDATE-New Transmitter ***UPDATE-2nd Transmitter 😭
Edit: Re-reading the aforementioned topic, apparently some transmitters keep functioning quite well despite a resistance exceeding 1000. Battery voltages dropping below 300 are another indication that the transmitter may fail shortly.