I have started using the built-in keyboard and have noticed that if I play a chord with three notes then the chord is held down for a small amount of time after I remove my fingers from the screen. This only seems to be the case with three notes, if I use two or fours notes for example then all keys release when I remove my fingers from the screen. Very staccato three note chords work ok but anything with a slightly longer duration (.5 seconds maybe) are sticky.

Odd, it is not doing that now since I restarted the app from when I was using it this morning. I’ll see if I can work out what I was doing before it got into that state.

OK, I have a reliable recreate:

1. Create a new song
2. Load DigiStix into a track, set it to sync with the host and record 4 bars of music
3. Hit pause to stop the recording
4. Open the keyboard in DigiStix or another AU and play a 3 note chord. You should see the sticky behaviour mentioned in the original post.

Hmm, weird, we can't get it to fail on several devices. Is this a sticking of the midi note only, or is it just the visual key stuck down? Does the key release if you tap it again or slide up to it?

Apologies, it seems my reliable trigger was not so reliable as coming back to it I cannot reproduce until I’ve randomly recorded, deleted, minimised etc but I’ll keep looking for a recreate to save you wasting time.

When it sticks then the notes continue to play and the notes stay coloured blue for a short amount of time after I lift my fingers. If I place them back down then in this state then it does not retrigger the chord, as far as I recall.

No worries! It sounds like there is a delay in the keyup then? There is a high priority thread that does the key down/up management but depending on other cpu resorces, it may be being starved. What device/iOS version, and is there other apps running in the background?

A more reliable recreate is to set up a second DigiStix track with some notes in it and have both tracks record a few bars. A lot of the time then selecting the second track and opening the keyboard triggers the problem.

If this does not work then deleting track 2 and opening the keyboard on track 1 has triggered it every time in my most recent recreate attempts.

The issue remains between closing and opening the song but goes away if the app is killed and restarted.

iOS 14.4.2 Air 4 with Safari and a few tabs running.

Hmm, it's probably not a cpu issue because that device is a monster. It may have something to do with threading with the 6 hardware cores. The hardware accelerometer is used to mimic key velocity, and it's a bit of a delicate system. Or perhaps an issue with that device itself, do you have another device you might be able to repeat the bug on? That might help rule out a particular device or particular model.

Another thing I just thought of is the system gestures (slide up from bottom) are 'deferred' whenever a piano keyboard is onscreen. So a little tab opens instead of the app swiping away. This was so it didn't have a delay in keypresses when the keyboard is positioned directly on the bottom of the screen. Maybe something to do with this? I can't seem to reproduce the bug.

I do have an iPad 7 I can try and reproduce on later. Thanks for persevering!