MQDH reports low framerate but other tools do not (Failed VRC.Quest.Performance.1)

Unity LTS 2022.3.37f1 / OpenXR

I first submitted my game a few weeks ago and received a VRC.Quest.Performance.1 failure (running < 60 fps). It was running at a solid 72 fps on Quest 3, so I borrowed a Quest 2 and found it was quite low (30fps or so) and went on to optimise the game quite a bit and brought it up to 72 fps on both Quest 2/3 consistently as per the OVR Metrics overlay and the adb logcat -s VrApi command

Now this is where things get weird. I resubmitted and received the same VRC1 failure again. I double checked the performance in MQDH and found that the fps look like a sawtooth pattern, where it reports 72fps and 19fps on alternate frames, seemingly at random. In some cases the low fps frames were reporting an early frame as well. The logcat VrApi command shows LAT (latency) as -1, meaning that the frame latency is dynamically managed by Phase Sync (which can no longer be turned off when using OpenXR in Unity). The game is running buttery smooth and I still get these VRC1 warning in MQDH on Quest 3, even when I set the refresh rate to 90hz where it runs fine. There's no way that the game can run at 18 fps higher and still somehow be dropping frames. It also isn't reporting any late or stale frames either so go figure. I think this could be an MQDH bug as none of the other reporting tools show the framerate drops but this seems to trigger automated failure during review and I have no idea what to do about it