VLT issues DELL S4112F / DELL N1524 (+ others)

Hi! 
I have a few DELL switches setup as VLT domains in the environment I’m managing. 

I recently got 2 new S4112F switches and set them up exactly as I have done before with a new VLT domain. 

I got one “4-port portchannel” (2 ports in each switch) going to another VLT domain and that is up and running on all 4 ports. 

I configured a portchannel on a single DELL N1524 and connected one port to switch 1 in the VLT domain and one port to switch 2. 

The portchannel goes up but only one of the physical interfaces. 

I get the following message in the logs of the N1524. 

mmxsw26-1 DOT3AD[dot3ad_core_lac]: dot3ad_lacp.c(2339) 845 %% WARN Interface Te1/0/1 partner priority 4096 is not same as existing members of LAG interface Po1 (4096). Not adding interface Te1/0/1 as active member of LAG interface Po1.

I have googled the logged message and it leads me to a few posts in this forum but none of them seems to explain what the logged massage means. 

I have checked and double checked the configurations, and everything seems to look as it should. 

I have other VLT switches setup to other N1524/1548-switches and they are ok. 

Any pointers? What should I look for?

If I bring down the active portchannel port the inactive one goes up. If I bring that interface up again, I get the same message in the log but on the other interface.