Here goes..
After the upgrade, observed this alert/error "unable to fetch configuration" & the Firmware status said "Up to date Current version: Not running configured version"
Gave the switch sometime to see if the alert/error goes away automatically as described in the Meraki Document & it didnt.
Then, after 15 mins rebooted the Switch & still there was no change.
Raised a case with Support
They went through backend troubleshooting to review the whole issue.
From backend logs, they were able to determine that a component used by the MS120 to perform firmware upgrades has failed to function as expected. As a result, the device was not able to successfully pull new configurations from the Meraki dashboard - unable to update any of its configuration settings. .
Support also tried to employ a workaround to the issue, but that failed too.
At this stage, support said they would initiate RMA.