Found this post on Tesla Forums from a couple days ago. Tesla service confirmed he was rolled back to 8.3 due to issues with 12.5 and 8.3 is the latest available for his build (see text message quote below from service). Still not clear which combination of factors are leading to some M3s being held on 8.3 but this clearly isn't just regular upgrade cycles taking time to get around to everyone.
FULL POST:
Software 2020.12.5 failed and now not available
Submitted by funkiegh on April 30, 2020
My 2020 model M3 AWD LR received in March with 2019 FW was upgraded to 2020.8.3 on 1st April; so far so amazing!.. However on 15th April a friend told me he'd just received 2020.12.5 with the new dashcam viewer - identical car (except for the colour) and delivered on the same day as mine. So I waited patiently for my turn - keen to get the on-board Dashcam / Sentry viewer,.. and waited for a week before contacting the UK support line. When I did, they told me it had been pushed out to me on 15th April but had failed, although I'd had no indication of the attempt or the failure. When I asked them to try again I was told the latest version available to me was 8.3 which I already have - so they told me to raise a service request, which I duly did. The next day I received a text message on my phone:
"Hi Mike your Model 3 is on the latest update we can deploy. There have been some issues with 2020.12.5 hence the rollback. Please wait until this update becomes available shortly. Please note we will not update firmware at customer request we will only push firmware if there has been an issue with a previous install or it is required to fix a issue with the car. We will cancel your appointment thank you."
Does anyone understand the reason for this or had a similar experience? As far as I can tell (Teslafi & Stats app) a vast majority of the fleet (>50%) has 12.5 with 12.6 a close second.. 8.3 is around 8%. Any advice?
Im still wondering what advice you are looking for, beside "just wait, and you will be updated to this or some other later version when they flag it for your car". My other posts were not trolling, just pointing out that your description of "lack of transparency" for updates exists everywhere, including tesla. Since you mention you are a coder, its unlikely you tell every end user every change that is made in your software.
Im not trying to be argumentative, just trying to point out that, yes, people who have been getting new hardware (many) have been regressed to some version prior to what they had previously. Easy to understand, in that its "likely" the software is loaded onto the hardware and they just install it, then activate it. We dont know, but enough have gotten downgraded from "whatever they had" that its a reasonable assumption.
No amount of "teslafi" or "Stats" sleuthing is going to make your car show up "faster" for an update. its entirely possible they stopped rollout of Version "X" for "reasons". They do that ALL the time. If you dont get 12.5, or 12.6, you will get 12.11, or 12.12 or some other version, in the next XXX (<3-4 week time frame).
Nothing you can do in all the sleuthing, investigating, etc is going to make tesla update your car faster, so the advice is "wait, and you will get whatever update they flag for you when they release it". If you find enjoyment with the sleuthing, wondering, etc... have at it. There isnt anything you can do to trigger your car to upgrade, though. They will flag it and it will update to some version they have for your car that includes those features "later". Non FSD cars are not being held from version 12.5 / 12.6.. many people without FSD have been updated to those versions.