Synthmaster One, Reaper, Linnstrument, stuck midi notes

[mek42]

I'm on windows 10, 64.

I recorded some midi tracks with my Linnstrument (while also having a key controller hooked up) for a couple arp presets. Sometimes during playback notes will get stuck in the sustain phase.

I've tried some things. I've "corrected overlapped notes" in case I hit two of the same note with the Linnstrument and I've tried some other thing on the Reaper side.

Then I used Union instead of Synthmaster One and had three error free playbacks. I re-enabled SM1 on one track and had the error again on the first playback.

Are there any setting I should check to tdy to fix this?