I just recently purchased a hAP ax^3 and it is now quite happily running on my network and supplying a point to point wire guard connection, I have upgraded it to router OS 7.20 but I am very confused by the version numbers, I have seen people reference numbers as if they are the latest version with regards to installing a Pi-hole configuration as apparently it requires containers which are included in the “latest version” but the version number they are using is greater than 7.20.
People are not always particularly exact, but
"latest (hopefully followed by the channel, i.e. alpha, beta, stable, long-term)"
is always intended as
"latest at the time of this writing",
and it is anyway a not fully correct way to identify a version.
If you really have to use "latest", the "proper" (avoiding confusion) way is to alway add the exact version number in brackets, i.e. "latest (7.19 beta2)".
Try reading 7.9 as 7.09 ...
Or:
Major version 7
Minor version 9
Or ninth release of version seven.
It will be evident that minor version 9 is lower/older than minor version 20.
It is a long standing issue with version numbering (not only in Mikrotik world) and the justification I have been given is "You cannot know in advance if there will be more than 9, more than 99 or more than 999 minor versions, so how much leading 0's are you going to use?"
And then there's "the third decimal", sometimes referred to as "patch number". Something like 7.19.6 ... which indicates that version numbers should not be read as decimal number at all.