Libre sensor "wait 60 minutes" on already running sensor

[PhilTU]

A number of users have identifed a problem using xDrip+ with Libre 2/2+ sensors. If a sensor has been operating for some time, after the initial one hour warmup, it was previously routine to start the sensor in xDrip+ and say "not started today" in order to bypass a warmup phase in xDrip. Some months ago this appeared to change.

The problem behaviour is that users are now told to wait one hour before being asked for calibration input, even though the sensor may be days old. There is also a one hour delay before data is sent to AAPS causing a break in the loop.

Previous discussion #4004

@AdLouwerse identified when the change of behaviour occurred - ~" Nightly build xDrip-plus-20250312-14494e7.apk works fine, the problem starts at nightly build xDrip-plus-20250323-0addc89.apk."

2025.03.12...2025.03.23

Originally posted by @PhilTU in #4201

[jamorham]

Does this only happen if users are running multiple sensors at the same time, like attaching a new sensor and then connecting it to xdrip later while another sensor has previously been running at the same time?

I can see the code that likely has been introduced that would cause this (thanks for identifying that diff) but I just need to understand the exact circumstances to ensure the fix is correct and doesn't affect those other changes that relate to overlapping backfills.

[PhilTU]

In general users had the Libre sensor running for a few hours before connecting it to xDrip - for example

"My Libre2+ was started with the LibreLink yesterday. When I today, like I always do when switching Libre, I stopped the old one, clicked the Forget Device, then scanned the new Libre and selected "Not today", xDrip would still display sensor warm up message and only after would I be able to calibrate it. Tried it multiple times."

The feedback isn't clear what happened with the previous sensor. Nobody explicitly said they were running two in parallel but it's quite likely they started the new one with the vendor app while xDrip+ was running on the extra half day life of the previous sensor.

Using the Fake data source I can reproduce Navid's experience that a 3h warmup is initiated even when you say the sensor started 3 days earlier.

[Navid200]

@jamorham If you point me to a prospective solution, I can test for G7 backfill overlap. It will take me a total of 20 days to test both possibilities.
I was working on a solution. I was adding a new field of started_warmup_at to Sensor.create.
But, I don't have a solution yet.

[Navid200]

I opened a PR that fixes this and have included a test release:
#4253

[Navid200]

This should be resolved as of the 2025.11.28 Nightly release.
Please let us know if you still experience it.

[PhilTU]

Please let us know if you still experience it.

unfortunately yes. I just updated to 2025.12.02 as I saw Libre mentioned in the changelog. Stopped the sensor in xDrip+, NFC scanned, did "Start sensor", said "Not today" and went to "Please wait while sensor warms up! (60 minutes) status.

Libre Bluetooth hardware data source, OOP2 from September 2025, stopping and starting sensor issue persists. OOP2 set to No calibration option in xDrip+

[jamorham]

@PhilTU In no calibration mode as soon as you receive a glucose reading then that message should vanish and you should see the glucose value. Can you recreate the problem and after a period when you would expect to have readings upload logs? Thanks

[PhilTU]

Will do. I agree that previously I observed that. This phone almost never connects with Bluetooth but I will test on another.

Edit - I rescanned with NFC and the wait 60 message did indeed go away.

Most of the dissatisfied users were using "calibration"