Different readings on my pump and Apple watch

I’ve been using my Apple watch to take a look at my readings. When I go to enter it on my phone tracker I often click on the TCONNECT app and the numbers match - along with my pump of course. But this morning my watch showed 147 while my pump and TCONNECT matched at 138. I waited a minute to see if there would be any updates but there weren’t. Now several minutes later they are in sync, all showing 153.
Has this happened to anybody else? I would expect the numbers to be in sync. No loss of signal recently. Thanks!

Hi Dorie. The phone needs to talk to the watch through Bluetooth or WiFi or if you have a new watch, through mobile data, and there can be times where the communication is “laggy”. I don’t use Tconnect and so my phone is my only g6 receiver. There can be times where my watch simply has old data. It resolves itself after a few minutes.

Yeah same! My apple watch is usually a reading behind but will catch up. So for example when I’m exercising I’ll notice 90 with a slight down arrow on my phone, but maybe 97 with a slight down arrow on my watch. It usually catches up quickly but there seems to be a delay fairly often!

My watch is connected via Bluetooth and was right next to my phone so no connection issues to speak of. They’ve and been identical before so this struck me as very odd. I guess I shouldn’t expect “perfection” - maybe I’ve just been lucky so far.
Thank you both.

It’s not a connection issue. It’s a update/lag issue. I see it from time to time. Phone and watch resources are deliberately slowed down to save battery power. This results in one device having an update before the other device. Im typically ocd about this stuff but I can’t let it bother me. Getting a BS on your watch, for all practical purposes, “continuously “ sure beats testing urine!

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Dorie @wadawabbit your “not synced” isn’t anything new. When body glucose level is changing, it is common to see different values on the Clarity app and t-Connect. The answer is quite simple even though both devices are programmed to SEEK readings from the G6 Computer [sometimes called transmitter] at 5 minute intervals - they initially connected to the sensor computer at slightly different times.

This can be observed by watching both sets of readings for a while and noticing that the same values will appear in the same order on either. That is one of the reasons that the US FDA on page two of the letter “approving” the G6 for insulin dosing states on page 2 that before using a BGL value for insulin dose that one should observe three consecutive readings.

Thank you @Dennis . I got my Apple watch last summer and this is the first time I’ve noticed it although I look at it fairly frequently. Occasionally I’ve gotten one number on my watch, and it quickly changed to the reading that matched my pump but never before had it lasted more than a few seconds. The info you shared to know, and like @joe @I’ve decided to try not to obsess over it although the “incident” did drive me a little crazy. I’ll try to forgive and forget this little “hiccup.” Thanks as always to both of you!


To save the tiny battery, the Dexcom receiver comminucates for a short time within a 5 minute cycle that lags behind reading the sensor value, and it communicates data to one receiver at a time. The primary receiver has priority. The wart-tch is a secondary display.

I see the same thing using the Xdrip+ app on my phone. It lags the Tandem pump’s displayed values, and is slower to re-establish lost communication. I suspect there’s a similar delay with the Dexcom app. app on , it lagsthe Tandem pump’

It could also be a glitch in the matrix. :wink: