Pump noisy after cleaning

[Klex]

Hi,

We have a fluval submersible pump as part of our new-ish tank set up.

I noticed to flow rate of water was down so took it apart and cleaned it.

While that solved the flow rate issue it now seems to be humming louder than it was before.

Any suggestions?

Check the position of it in the tank, is it in exactly the same place? Could it now be resting on something thats causing a vibration? Thats usually the issue when ours does that.

It can only sit in one position because the outlet screws through a hole in the back on the tank (all the filters etc are hidden in a section at the back)