Following a recent Microsoft “update”, my lock screen (calendar) notifications stopped working. After trying a number of possible fixes posted elsewhere online (none of them worked for me) I looked into the Focus feature in System-Notifications-Focus – and found in there the Do Not Disturb checkbox had been automatically selected following the recent update. After I de-selected that option, I got my lock screen notifications back. So, this fix worked for me.
Despite the Do Not Disturb feature being de-selected elsewhere on my system by me – the Focus feature Do not disturb feature took override precedent over my preferred settings!
I know M/S is making Calendar redundant and is pushing Outlook(new), I wonder if crippling calendar notifications with the Focus Do Not Disturb “glitch” was a way to try to influence users to switch to Outlook (new). By the way, they seemed to have also changed the “try the new Outlook now – you can always switch back later” message to “now you have switched to Outlook (new) you can’t switch back and will be automatically redirected to Outlook (new)”. So, be warned, if you don’t want to be stuck with the “new” Outlook (new) feature, don’t select “Try it now” option.