Have you had the Mother 32 for long? Perhaps it needs re-calibration?
Could be the Mother 32, not all synths track particularly well or over a large range.
I have a Dreadbox Erebus V3 and the manual specifically talks about tracking being usable only within about an octave. It's fine via MIDI though.
Yeah and interestingly the Moog Mother 32 VCO is beat by the Doepfer High End VCO, which has a stable range of ten octaves!
This was a common problem back in the day, and is one of the problems which midi obviously fixed.
But that is why you want to use CV; for that authentic 70's synth sound that goes out of tune ever-so-slightly as you go up and down the octaves and makes people on lsd lose their mind!
I dunno why MIDI helps with accurate pitch tracking, but it does. That along with DCO's really cleaned up the issues that synths had in the 70's. A discussion on another forum recently addressed the drift that VCO's have and how many engineers have added a drift parameter to their oscillators to give the phasing effect that old multi VCO synths had.
When I hear some of that early 80's synth pop which has a very slow and very noticeable waver to the pitch, I have often wondered if that was the oscillator drifting around the pitch frequency or a really weird idea of what constitutes "great sounding" vibrato.