It can be a compression low, especially when sleeping or leaning on the sensor.

I've never had luck with continuous glucose meters, I've tried the libre and dexcom. Im waiting to hear back from my insurance about Eversense, the implant that's put in every 6 months. It's suppose to be more accurate

CGMs are just devices and they are not 100% accurate. Some of that is due to clogging of blood entry point for the reading. If you question your level shown by the CGM, best to due a finger trick test. Last May my CGM was very far off and I was low. Lucky I tested and now I always test if any doubt.

Compression lows are the most common reason.

Sometimes pressure on them. Like if your sleeping on it, has caused this for me.