Can the last active time stamp on Facebook change without going online?

[Sanity Not Included]

Sometimes, the last active time stamp on facebook messenger while logged onto a computer changes for a user on my friends list every 10 or 15 minutes without the green dot ever showing they were online when the last active time displays "1m" I was wondering if the time stamp resetting this way means the user has been on facebook messenger mobile app and has replied to a message or what could be the reason this is happening. Sometimes the user will acquire a higher last active time display when it shows they've logged on and the green dot appears next to their name, but other times, they will keep on going from last active "10m" or last active "15m"

[Linda]

It's been my experience through tests with my friends that the last active timestamp is the most accurate.

[Daniel]

No it Can Not Change Without Going Online