7875 + 5.9 + E85 + Megasquirt

Haven't had a lot of time to tool around on the car with work but have added a few new gadgets to the Megasquirt - I installed a flex fuel sensor, transmission speed sensor (mph) and a good fuel pressure sensor to help me debug this nagging issue I've had with the AFR going really rich in boost.
Trans speed sensor:
Screen Shot 2021-11-04 at 7.05.30 PM.png

Flex fuel sensor with -6an fittings.
Screen Shot 2021-11-04 at 7.06.32 PM.png

fuel pressure sensor:
Screen Shot 2021-11-04 at 7.14.33 PM.png

Now that I have accurate fuel pressure data I've logged runs with and without the 1:1 boost reference connected and it seems my issue is somehow related to climbing fuel pressure under boost. AFR is much better without the boost reference connected, but obviously that's not a long term solution, especially when turning up the boost. So, I rebuilt the fpr today (new diaphragm, Aeromotive 13001). I've cleaned both filters but am still seeing AFR drop off the data logs (below 10.10) when getting into boost. My base pressure is 58 and of course it hovers a little around 50 at idle with the vacuum removing some pressure but the logs show it rising at pretty much 1:1 with boost so I believe the fpr is working as designed. Just can't figure out why the AFRs fall off the log. In a longer run it will eventually come back to targeted AFRs under boost so I know my VE table is accurate. Any thoughts/ideas guys?

fpr boost reference connected: You can see where the AFR drops to 10.10 at 7.1psi
fpr-connected.png

fpr boost reference disconnected:AFR is 11.00 which is the target, 7.1psi.
fpr-disconnected.png