So first, if the oscillator sync is enabled, you will never notice any tuning problem, so turn it off.
If oscillators 1 and 2 are set to the very same value (with the precision mode for example) and have just been calibrated, well… it’s analogue baby
I would not be surprised to still hear frequency beats.
About their frequency: the beat frequency equals the difference of frequency between oscillator 1 and oscillator 2.
I won’t be that guy that knows how quick/slow should be the beating of a “normal” Phatty.
I’ll be that guy who tells you that it’s analogue, it lives, it moves, and provided it sounds good to you, don’t bother.
If you want the perfect match, set the frequencies so that the beat is the slowest possible, then enable sync.
About your problem of perfect fifth (first post), I have no idea: I would have told you to calibrate your warmed synth, 2-3 times if needed. But as you’ve done that already, I don’t know. Hope you’ll solve that