Latency Mac Studio, Cubase 12, Motu (64 Input Channels, 32 Output Channels)

My configuration is
an new Mac Studio M1Pro 64G Ram, 4T SSD
Cubase 12

Motu Interfaces AVB over USB
(in Sum im using 64 Channels to Computer and 32channels from Computer)

Motu 1248
Motu AI24
Motu AO24
Motu Stage B16
Motu Stage B16

AVID S1, Avid S1, Avid Dock

The latency in Cubase is shown about 3ms in/out at 64 samples.
There is for example a recorded live session with 24channels at 44.1
No Plugins at all.
When I try to make an overdub (guitar, Voice,…) there is listening the Motu Mixer no obvious latency (so i suggest the interface can deliver in time to the computer), but when I switch on the monitorbutton in the recordingchannel in Cubase there is a non playable latency.
So I suggest the latency is produced by Cubase or in the way from the computer to cubase.

I didn’t find any description how to solve this.
Are the amount of configured interface channels a problem?
I didn’t find any hint that the amount of interface channels is changing the latency.
Neither in Cubase nor in Motu.

I had the same problems with PC, thats why I thougth a new Mac could solve the problem
At the moment I’m very disappointed, so I would like ist if someone had ideas about it.

Txs in advance


When you say that you have no plugins in the project, did you make sure there are also none in the control room (if you use that). That is usually something people tend to forget, and if you have say something like sonarworks on there, that can add some hefty latency.