I'm using Lumia 535 with Google account and (default) setting of displaying nearest calendar event in the bottom part of my lock screen.
Even though my phone syncs details with Google account (e-mails, contacts and calendar events) on regular basis (every 15 minutes plus sometimes manually) and even though system calendar is up to date, I can see some completely outdated entry on my lock screen.
Most time it displays event, that I no longer have in my calendar. After most (manual or automatic) account sync, I can see that this lock-screen calendar entry does not change. And even if it does, it changes to another "ghost" event, that I had in my calendar for example yesterday or edited it (in my Gmail) and changed its title like about hours ago.
For the sake of testing, I have even installed extra calenda ("SimpleCalendar"), next to system one, to double check, if everything is OK. Both calendars shows up-to-date entries in my Google calendars and correctly synces with all recent changes. Only lock-screen remains the problem.
Does anyone recall similar situation and know, what can be causing it or how to fix it? My wife has Lumia 735 with the same software version (Denim) and for the past ten months, she has been using it, we have never encountered such weird situation.