@isla112: To troubleshoot the issue, please head to the Messages app > Tap the 3 dots in the top right > Settings > Notifications > General Notifications > Alert (tap to select) > Show As Pop-up (On) > Lock Screen (Show Content). Go back and do the same for 'New Messages', then head to Settings > Notifications > Brief > Brief pop-up settings > Edge Lighting Style (choose your preferred option) > Show Even While Screen Is Off (toggle this on).
Next, head to Settings > Lock Screen > Notifications > On, and choose your preferred settings below. Let me know if this helps.
