This may be a stupid idea, but often the best way to find a problem is by halving the possibilities each time until its located. That is quite a long (and impressive) list of hardware you got there so your loop has a lot of devices, fittings, and tubing in it. Would it be possible to install a temporary piece of flexible tubing at 2 points in the loop, effectively cutting a large chunk of it out of the "circuit"? You could detach the hard tube and attach the temporary flex tube to the pump output. Then break the loop half way through and attach the other end of the flex tube there. Cap off the chunk that you cut out. Now your loop is half as long, with half of the devices and fittings bypassed. If leak detection is still indicating a problem, cut the loop in half again. If leak detection is not reporting a problem, check the other half of the loop. Eventually you will have a loop that is pump - problem device - pump.
Leak detection not reporting a problem in whatever section of loop you have active will also confirm that leak detection is actually working properly. You could also validate that leak detection is working properly by making a super short loop, like pump - rad - pump. I'm not sure if its OK to connect the pump output directly to its intake with a piece of flex tube, but this would be the shortest loop possible. Of course you should have only the active loop components powered while doing this, along with full paper towel brigade. This is also very intrusive trouble shooting so there is a risk of causing a leak that was not there before. I would do a meticulous physical inspection first before I started chopping the loop up with a test flex tube, but it sounds like you have pretty much already done that. Good luck, and please do post your findings. That is a lot of loop to troubleshoot.
I guess I could but I dont own any soft tubing fittings though, I guess I could pick a few up, but atm I don't own any. I can try that though removing a big section of the loop like the nexxos monsta being the biggest thing I cant control as it crammed into this case and barely fits, but it does. Just have to take everything off of the case to get it to it and my reservoir and fans are all attached to it also both pumps as well. So its the mainstage in my loop. Could try removing that section see what happens
Also off-topic question but shouldn't a power-adjust3 be able to power a Darkside uv led strip a 12v one? it has a 3pin plugin aquaero6 powers it no problem I figured since its a power based thing the poweradjust3 should be able to power it. I get nothing when I plug it in to the pa3, I plug it back into the aquaero6 it works just fine again.