A banner appears at the top of the page saying "Your login identity has changed in another tab." What does this mean? Can I log in to two companies at the same time?

Only one login account can be maintained in a single browser at a time. When you log out or switch to another account in another tab, other open tabs will display a persistent banner reminding you that the data shown on that tab is still from the previous account, for example "Your login identity has changed to another account in another tab...please refresh to continue" or "You have been logged out in another tab." Clicking "Refresh" will first warn you that any unsaved edits will be lost; the banner will automatically disappear when your identity switches back to the original account. To use two accounts simultaneously (for example, a company account and a buyer account from another company), use different browser profiles or incognito windows. Additionally, one email can only belong to one company and one account in Patisco.