Fan noise all the time

[zamboknee]

Ever since upgrading my 2015 MBP 15" retina to Big Sur a few weeks ago, it seems like the fans kick on QUITE A LOT.
I check the apps that are using a lot of battery/CPU and it shows mostly Firefox but even with non-intensive apps and work being done the fans kick on.
Any idea why?
Is this maybe a PRAM reset away from fixing?

 

[zamboknee]

Wondering if it has to do with these multiple instances of the same things in Activity Monitor...

 

[Andrea Filippini]

Ever since upgrading my 2015 MBP 15" retina to Big Sur a few weeks ago, it seems like the fans kick on QUITE A LOT.
I check the apps that are using a lot of battery/CPU and it shows mostly Firefox but even with non-intensive apps and work being done the fans kick on.
Any idea why?
Is this maybe a PRAM reset away from fixing?

It's a common issue after upgrading any OS and it's due to spotlight reindex activity.
Normally a couple of weeks are enough to rebalance the OS (and the fan noise).
If it doesn't work, do PRAM and SMC reset.