Oh we missed the question "is anything else in the outlet".
Look at the problem devices label and see how much power it uses.
Then you can find a filter that is rated for the load.
An XPPF is fine for small loads but pushing it to its 5 amp limit may result in smelling hot.
The Smarthome 1626-10 FilterLinc is rated at up to 10 amps and has an unfiltered outlet on its front cover for another item. I have my UPS on a FilterLinc. The UPS is in the filtered outlet and my Insteon PLM is in the unfiltered outlet.