When I set a timer prior to iOS 14 it would appear with the countdown on the lockscreen, it doesn't in iOS 14 and I can't seem to find a setting for it. Has anyone else hit this and solved it somehow?
I just tried on iPhone 8 on iOS14 and the timer still appears on the lock screen for me.
I had a similar issue on my Watch 4, the timer complication randomly stopped showing the countdown and just showed the 30 minute timer recommendation to start. Once updating to watch os 7 the live complication started again!
So maybe a few restarts or the next update will reset the broken code for your timer.