Here's a switch that I cleared nodealias stats on today. You can see from the command line that the "Time Last Learned" column is set to today.
But if I query ctAliasMacAddressTime or ctAliasInterfaceTime with mibtools it shows that the time is 141 days which relates to the switch uptime not the nodealias last learned time.
So would this be a bug instead? Or is ctAliasTimeFilter, which doesn't give any results on exos, be the right mib to use if it were supported?