Scanline Sync Setup Issue - Help Required

[erinexplosives]

Hi, I badly need some assistance diagnosing an issue I have run into setting up Scanline Sync, specifically for usage with the Dolphin emulator.

About a month ago, I managed to snag a brand new PC CRT I found when browsing online. I was quite happy, as it meant I could do emulator speedrun practice on a CRT. When playing on console I use a consumer set, and having to practice on a flat panel was quite annoying. I am enjoying it quite a lot, but do feel the latency penalty from playing with v-sync enabled and not being able to rely on VRR as I did with my flat panels.

About 2 weeks ago I read setup guides on setting up Scanline Sync to get the best of both worlds. Initially I was having issues with a fast scrolling tear line that was moving down the screen (represented clearly by RTSS' 2-bar overlay). Eventually I guessed that this was because my CRT's refresh rate was currently 60.000hz, and Dolphin likely outputs at 59.94hz, the NTSC standard. I used CRU to create a new detailed resolution and entered 59.94 as the refresh rate, creating an "Actual" refresh rate of 59.952hz. I don't know enough about monitors or CRU in general to know why there was a difference, but selecting this new 59.952hz refresh rate kept my tear line locked in place, and I was able to very easily keep it off-screen on my 640x480p 59.952hz resolution.

Fast forward to today, and this seems to no longer work. the 59.952hz resolution has the tear line slowly moving down the screen (but not rapidly as the 60.000hz refresh rate was). I tried using Nvidia Control Panel to manually create a 59.940hz resolution instead, but that frustratingly has the tear line moving slowly UP the screen instead. I have doubled checked that RTSS has the proper refresh rates reported when right clicking the FPS lock field, and that the scanline sync field always has my CRT selected.

Some additional details:

- I am using the Vulkan renderer in Dolphin
- the [Framerate] section of my Dolphin.exe.cfg is as follows:

[Framerate]
Limit=0
LimitDenominator=1
LimitTime=0
LimitTimeDenominator=1
SyncScanline0=0 <-- (was -16 when working 2 weeks prior)
SyncScanline1=0
SyncPeriods=0
SyncLimiter=3
SyncDisplay=2
PassiveWait=1
ReflexSleep=2
ReflexSetLatencyMarker=1
SyncFlush=2

I did take a video of scanline sync working 2 weeks prior with the 59.592hz refresh rate, but I can't seem to link it in the forums. If anyone would like to see if I can provide it elsewhere.

If anyone can help me with this it would be greatly appreciated!