Thank you for posting here in the Community about the unavailability of the Switch Company option.
Currently, we are conducting an in-progress investigation (INV-109353) wherein the Switch Company option is missing in the Settings. Please know that our product engineers are working hard to resolve this issue.
With this, I recommend contacting our QuickBooks Online Support Team so that they can add you to the list of affected users:
Log in to your QBO company.
Select Help (?).
Click Contact Us and choose a way to connect with us: