That very well may be true. But if you believe them there was a hardware change that forced it... that only furthers the OP core problem: he needs to re-test everything. A few bug fixes is way different than new hardware...
And to OPs point, what could have done differently so that when he orders a SKU, all devices are the same? Or, the "plan" is just "wait to see what comes in the mail" to determine your test cycle? As an home router, it matters less. But as something "embedded" in some IoT system, this last thing you want.
As I already wrote above: “Well, yes that is the fact of life with MikroTik. When you are a shop that believes in validated software releases that you test and then can use for years, then probably it is not the proper equipment to buy.”
Ordering a device by type or SKU does not guarantee you will receive the same hardware. When you need that, you need to select another manufacturer. I can tell you that at least one other manufacturer of this type of equipment has the same policy (changing hardware revisions without changing type name), so that may not be very easy.
Maybe when it is really very important, some more specific communication with MikroTik sales and they local distributor is required. They undoubtedly can give information about such cases when you buy in some quantity. I already gave you my reasons above why it is probably not preferred to communicate this information in public (old stock losing value when rumor spreads that “a new version” is available too).
Amm0 has got the correct understanding of our issue. Currently, it’s always a surprise when we have to revalidate that our custom scripts etc still works on the newest shipment of Mikrotik. Each version of routerOS has it’s own bugs and issues, and when you need to ship off a large quantity of KNOT routers to customers, then must indeed be quality controlled. And when you ship a large quantity of mikrotik, you eventually get every issue possible. It is much easier to handle issues, when you know that most of you routers are on predictable routerOS verisons.
Knot also runs on 4g cat-m an nb-iot networks, which makes it basically impossible to upgrade firmware version over the air, so once a knot is deployed in that manner, you cannot keep it up to date any more.
Well, as I wrote, when you do not want it to be a surprise, communicate with your distributor and with MikroTik Sales. When you buy larger quantities they undoubtedly can tell you what you will receive at the time when you place an order.
Of course that will not mean you will always get the same thing, but at least you can be prepared.
I recommend that the OP clearly distinguish between the Factory Firmware (RouterBOOT and also the minimum accepted RouterBOOT version) on system/routerboard
and the Factory Software (minimum accepted RouterOS version) on system/resources.
(then the device-mode must be considered, but that's another story)
For example,
you can easily install 6.49.19 on a machine with the "Factory Software" at 6.49.17
that ships with RouterBOOT & RouterOS at 7.20.2.
The Factory (Reserve) Firmware has absolutely no bearing
on the minimum RouterOS version you can netinstall
[but you cannot update the Current (Main) Firmware (RouterBOOT) to a lower version].
One would think that someone doesn't build a business on the thought of shipping devices that won't ever be updated and will obviously become another botnet in the future.
Yet here we are.
Good luck.
