Korg Monologue trill and volume control

Hi there! New to the forum but a fan of Syntaur and Synth Wizards. I have a Korg Monologue that has demonstrated two issues. The first is a trill that is emitted intermittently and only occasionally. I cannot reproduce this issue on command, it seems to show up after the unit has been on for 20 minutes or so and beeps every 15 seconds or so at a considerably lower volume than the oscillators but enough to ruin a recording. The second is an occasional loss of control of the volume. It will get stuck at about 75% of max volume and working the knob has no effect. This has been remedied by powering the unit down and back on, but only some of the time. I have read about and seen these issues demonstrated on youtube, but no real solution has come my way. Korg was also less than helpful. Let me know if you have experienced this or have any suggestions, thanks!