Thanks for sharing this, we encountered this issue last week and came across your post. We had been holding back the firmware for an MX95 also for some time on the 16.6.6 build as the 17.x firmware and 18.x firmware right up to the latest 18.107.2 build was causing issues. Web Dev testing the issue was running 'time curl -v <webpage>' would either timeout or take 20-30 seconds on the newer firmware, rollback to 16.6.6 and instantly load. Changed the the client tracking mode from MAC address to IP address per your post and the issue was resolved. ... View more

Posting if this helps others, upgrading MX units to 18.105 which only have cellular/4G internet (ie, no ethernet internet connectivity) there appears to be a bug which the unit reports on the dashboard as upgraded to 18.105 however the device goes offline for 15 minutes every 2 hours. Meraki support engineer confirmed the device was stuck in a upgrade loop and was actually still running 17.10.2 firmware even though the dashboard says its updated. Telling the MX to reboot via the web dashboard 'fixes' the issue for a few hours before it comes back again. The actual fix is to pull the power out of the MX and reconnect, the hard power off/on appears to force it to update correctly. ... View more

I just had a similar issue with an MX95 where Internet 2 interface failed to detect a cable connected following upgrade from 17.8 to 17.9. Troubleshooting with Cisco Meraki support for an hour and found changing the link negotiation from Auto to 1gb full would bring the interface up, however it then caused Internet 1 interface to fail.   Not sure if this information might be helpful to others but it appears to be some type of bug with the link speed negotiation. ... View more