36-64 on 5ghz-1 & 100-140 on 5ghz-2
Note that I can't speak for the ZenWiFi XT8, both of mine are nodes to my AX11000, so there may be a problem with the XT8 I cannot check.
I have restrictions on where (power availability), and what (space availalbe), and proximity (far enough away from other node), I can put the nodes so I can't really use one of the XT8s as the main router.
Anyway, that doesn't really tell whether you can get 160MHz.
For example I can get 160MHz on the low band and I have 36-64 listed and they are contiguous, ie. each seperated by 4.
But I have 100-165 listed on the hi band but they are actually 100-116, 132-140 and 149-165, so none of those ranges give me the 8 contiguous channels needed for 160MHz.
So I know I can't get 160MHz on the high band DFS channels or not.
According to WikiPedia (may be out of date), in the IK:
You should be able to get 160MHz on the low band but you will need to use DFS channels and if the router detects any radar signals in any of the DFS channels you won't get 160MHz.
It also looks like you should be able to get 160MHz on the high band, again provided you can use those DFS channels.
Check the wireless log to see a better description of what the router thinks is available, armed with the knowledge you need DFS channels, they may have been excluded due to radar signals.
There's also implementation details around what is done if radar signals are detected which I'm not sure of, again look and see if the router thinks it can use the needed channels in ->System Log -> Wireless Log.