Hey @Leone,
Really sorry to hear about this…this is odd behavior and definitely not the way things should be working.
To try and get to the bottom of this, can you help address each of the following points?
1. Does this happen with literally every event you try and create on your site, no matter what its date and time settings? Or do only some events seem effected?
2. If only some events are effected, can you take screenshots of the edit-event screens for these events and post them to Imgur.com, and then share links to those screenshots so we can take a look?
3. If you head to Settings > General in your wp-admin, your “system information” says your timezone is Los Angeles. If if you change this to just “UTC+0”, are you able to recreate these problems with event times?
Thank you!
George