Can I keep two Messenger accounts signed in on the same phone at once?

On Android, many phones (Samsung, Xiaomi, etc.) have a built-in Dual Apps or App Cloner setting that makes a second copy of Messenger, so both stay logged in. iPhone does not allow that natively. Messenger's own account switcher also holds multiple accounts, though only one is active at a time.

Same issue here after the last update. The fix above sorted it.

For truly side by side (both visible at once), a desktop unified app lets you add the same app twice as separate accounts. On the phone, Dual Apps is the cleanest for two logged-in Messengers.