Sorry to reopen such an old thread, but I think I may be experiencing the same, or at least similar, issue as the original poster. Short story is, loops 7-10 randomly lock up in either an on or off state. The lights under the foot switches turn off and on as they should, but the loop does not follow the switch state. Sometimes it will be that I'm playing with loop 9 on for the Ventris, and after turning that loop off, the loop stays open with the Ventris affecting the signal. The light for loop 9 is off, and the screen shows it's off, but the pedal is clearly still open and affecting the signal. And the opposite happens as well. I'll be testing a different pedal with loop 9 off, then I'll try to turn it on with the foot switch. The light turns on under the switch, but the effect does not get added to the signal.
A little backstory... I'm in the process of resurrecting my pedalboard that has been out of commission for awhile. The first thing I had to do was install a new screen on my PBC Mastermind. That all seemed to go smoothly, and after installation, the screen is perfect. I then started the re-wire with the goal of running my Strymon Flint, Source Audio Ventris and Strymon Timeline in parallel - loops 8-10 - and then later adding a Strymon CloudBurst to loop 7 and also run in parallel. I got through all of the wiring in the mono-only loops 1-6, and everything was working as it should. Then I started working on my TRS-TRS and left/right-TRS cable for the Strymon Flint, which is where things went haywire.
I have the V1 Flint, which requires a jumper to be set internally to receive a stereo signal in the single input. I made sure the jumper was set correctly before testing the patch cables I created. Also, after creating the cables, I tested continuity with a digital multimeter, and everything is right. Tip to tip, ring to ring, and sleeve to sleeve all complete their circuits, and there are no sounds emitted from the multimeter when testing tip to ring, tip to sleeve, etc. More on this below, because I have since confirmed the cables are working.
Now to more information about the problem. After I created the TRS-TRS cable to go from the send of loop 8 into the Flint input and the right/left-TRS cable to go out of the right and left outputs of the Flint back into return of loop 8, no effects were getting applied to the signal. I set the PCB to Loop mode, turned on only loop 8, and only my dry guitar signal came through my amp, so the patch cables were carrying sound. I did some troubleshooting for some time to see if it was my cables or the PCB, and thought at first it was my cables. Then I hooked up the Ventris to loop 9, and everything worked. While I couldn't test my TRS-TRS cable for the Flint, I did test the left/right-TRS I created going back to the return of loop 9, and it worked. So something had to be wrong with my other cable or something in the PCB.
I kept fiddling with things, and then saw the same thing happen to the Ventris in loop 9. I was playing with loop 9 in the on position and the signal was effected. I then turned loop 9 off, but the loop was still open as the Ventris' effect were still applied to the sound as described in my first paragraph. That got me to thinking there's a glitch and I unplugged the PCB and turned it back on. After that, everything worked and I thought it was fixed. However, a couple minutes later, it started happening again.
I can't reproduce exactly what causes it, but when the loop gets locked in the on or off state, I simply unplug the PCB and plug it back in, and everything works correctly for a couple of minutes before going out of whack again.