The MX sizing guide is updated with the new models as well. Specs is pretty much on par with MX85. A little bit disappointed that the expected performance with IPS enabled is 600Mbps and not 1Gbps. MX Sizing Guide and Principles - Cisco Meraki Docume...

Could it be related to this? Solved: MS Switch Is Unable to Relay 802.1x to Cisco ISE - The Meraki Community

The release notes for MR 30.5 (beta) mentions "Intermittent connectivity loss for Windows client devices". Not sure if it addresses the problems in this thread but could possibly solve some of the issues. We will evaluate as soon as version 30 is in ...

Could the issues in this thread be related to Re: Radius Authentication Issues - The Meraki Community

We updated our MX84 HA yesterday. Everything looks fine so far.