I've been trying to use my 2018 Spectre x360 model 15t-ch000 with several 5GHz 802.11ac access points in a 2x2 MIMO configuration with no luck on the DFS channels (above 5260 MHz and below 5745 MHz or ch 52 through ch 149. This means there are only two 80MHz wide channels for 2x2 mimo, and most all well engineered access point layouts won't accommodate the Spectre x360 w/ intel 9260 wifi addons because the laptop won't accommodate two contiguous blocks of 80 MHz spectrum allowing dual chain 2x2 mimo channels.
Has anyone else encountered this? It means you can not get 867 Mbit/s throughput! I'm maxing out at 45MB/sec on local transfers of 1GB files on my 2018 x360, while my 2017 model could get 89 MB/s transfer rates to my NAS on the same 802.11ac access point. The wifi driver for the 9260 is 184.108.40.206 dated 9 MAY 2018. The laptop can't even see the wifi names of any frequency above 5240MHz and below 5745MHz, which wipes out all the new spectrum the FCC opened up in the U-NII-2C blocks. I've tried this both with AT&T uverse residential equipment as well as Mikrotik carrier grade high power wireless access points & routers. They don't show up on the 2018 spectre.