When a note (or sequence) ends before the delay starts, it will yield weird results. Most of the time it will simply not be delayed (i.e. the wet signal is silent) or it will play the delayed sound once the effect receives another input.

Steps to reproduce

Start LMMS, add an delay effect (preferably with feedback option), and play a short note. Or take a look at
this example project showcasing the behaviour for a couple delay effects with delay time set to a quarter note.

Expected Behaviour

All sounds are delayed/echoed properly.

Actual Behaviour

In the example project:

• the first pattern is echoed/delayed in none of the instruments
• when the second pattern starts, the delay of the first one plays on top of it (at least in the top 3 instruments)
• the third pattern is played correctly by all effects since it's a quarter note long
• if the sound hasn't gone silent before the fourth pattern starts (that should be on all but Echo Delay Line), it will be played correctly
• because of the gap before the fifth pattern, the sound will become silent again. The pattern will play like the first one

Also, if you hold a piano key after the last pattern, you can hear the proper delay for that pattern.