We also have problem with notebook with Intel AX201 for a long time, we have also tried different Intel drivers and AP firmware 10.4.3.0, 10.4.4.0, 10.4.5.0 without success
There is not an Extreme investigation into this issue. It is currently viewed as an Intel issue and we have updated the article you shared. Also, these issues were not found during use of the IQEngine/Aerohive devices. The case the article is from was for WING devices.