Mouse input lag on 2019 Mac Pro

Ok, this is a bit weird. Usually, I have the Mixer as a separate window open just behind the Arrange so I flick back and forth so if I change track/channel in the Arrange then it will also change to that track/channel in the Mixer.

If I minimise the Mixer window, the amount of mouse click/keyboard input lag suddenly greatly decreased. The window can't be completely hidden behind the Arrange that makes no difference. But minimised in the dock no problem.

I'll try this on a heavier project and/or revert to using the one in the Arrange (it's always felt a bit cramped to me which is why I use the Mixer window) to see if I get the same performance change. What could be causing the mixer to require all that additional processing? Occasionally I get pink bars on one or both of the monitors when I reboot or wake the screens up (they're LG so switch off after 5 mins). Could this be a GPU issue?

So with the separate Mixer window no longer open, performance has noticeably improved. I hadn't experienced that level of a cpu hit in Logic 10.5.7 (on the 2012 MP) so I'm curious as to why the Mixer window in 10.7.7 would be gobbling up all those cycles? Surely there are users who have the mixer window on a separate screen? I even noticed the lag with the mixer on a second display without Pro Tools open.

I'll keep an eye on larger projects and see if editing audio (trimming the start of audio files, adding region automation for dB volume, CC Modulation etc) brings it to it's knees again.

Both the Apple wireless mouse and a Kensington usb trackball, this is also affecting keyboard input as well such as creating a duplicate track (ie two tracks but the same channel, mute one and both become muted)

As the system is racked I have a USB extension for the usb, however I also tried this via a OWC Thunderbolt dock and the same issue persisted making me think this was either a Logic issue, or an OS issue as this laggyness is also sometimes seen in Finder when Logic is open

A couple of media composer YT videos mentioned it due to connection issues for Pro Tools PCIe cards and Universal Audio cards/interfaces. I used to reboot with a FW800 interface without too much issue so I imagine a TB3 interface shouldn't have issues.

Just to clarify, a full shut down then power up as opposed to just a daily reboot?

Both the Apple wireless mouse and a Kensington usb trackball, this is also affecting keyboard input as well such as creating a duplicate track (ie two tracks but the same channel, mute one and both become muted)

• I have a habit of deleting undo history before saving and after large tasks I don't need to undo like deleting a load of unused instruments, Undo set to 100 as well

• I save as a folder as well, never used packages so selecting Save As... and saving it Project v1.1, then Project v1.2 all within the same folder which also makes client recall easier. I've noticed that doing this can reduce a 100mb session down to around 40mb even when deleting undo history between saves
• When I had activity monitor up the only things that are jumping up are Logic and ProTools but not by much.

I do use Summing aux stacks which have aux channels within them, have these been known to cause performance issues?

I'll give the PRAM reset a go, on my old system I would reboot every morning but this system I saw reports that it was better to leave it on and just Lock Screen when not being used. Is a daily reboot preferable to refresh/reset the memory?

It's a stock 8GB card as I assumed that that would be more than capable especially as I'm not running at native 4K on these displays. I could try running the Apple Hardware Test to see if that picks anything up.

To confirm, both LPX windows are on the main display with PT's video using the second display. I'll try avoiding the Mixer window for now and see if there's much improvement when adding Midi CC/automation in a region.

So there shouldn't be any routing/processor/performance issues or glitches if you set up multiple summing stacks with 4-8 auxes (ie sub groups & fx channels outputting to the summing stack) inside them?