MSC: Messages can't cross each other

if I try to move message2 just 2 cm above, one gets this:

But it would be expected that:

"Message2 to start after Message1, but stop before Message1"

• Add lists of events per instance
• Add list of comments
• Generate single Event list out of per instance lists
• For adding events action: refactor to use an API to operate on per instance event index
• For adding events timer: refactor to use an API to operate on per instance event index
• For loading files coregion: refactor to use an API to operate on per instance event index
• For adding events comment: refactor to use an API to operate on per instance event index
• For adding events condition: refactor to use an API to operate on per instance event index
• For adding events message: refactor to use an API to operate on per instance event index
• Adapt loading events from file
• For removing events: refactor to use an API to operate on per instance event index
• For moving events: refactor to use an API to operate on per instance event index
• Support crossing events in graphics view
• Remove single list of events
• Test test test