Downgrade to Sonoma in Mac Studio M2

zbookvc wrote:

It comes with Sequoia so you can't downgrade with the normal way using Internet Recovery.

Not so quick there ...

M2 Mac Studio Ultras were originally delivered in June 2023 with Ventura (13.4) preinstalled so it is possible that the refurbished model the OP purchased may be one of those. If so, it may be downgraded to Sonoma or Ventura even if during the refurbishment it was installed with Sequoia. If that's the case, Internet Recovery should work to reinstall Ventura but perhaps not Sonoma.

OTOH, if the OP's Mac Studio was a later delivery that origianlly came with Sequoia, then a downgrade is not possible.

Depending on the original delivery of the Studio, it's possible it came preinstalled with Sequoia, in which case downgrading to Sonoma is not possible.

You said it was refurbished. If you look up the serial number you should be able to identify the original purchase date, which may help indicate the version of macOS that was delivered with it.

• Your model (M2 Studio Ultra) was produced from June 2023 to March 2025. Sequoia was released September 2024, so Mac Studios delivered after that date were likely to have come with Sequoia preinstalled.

Mac Studio (2023) - Tech Specs - Apple Support (CA)

It comes with Sequoia so you can't downgrade with the normal way using Internet Recovery.