Point a remote at your 'phone and press a button, if you can see light from the remotes led your 'phone camera is infra red sensitive, most are but some are not.
If you have a 'phone that is infra red sensitive point it around the room when its dark looking for sources of infra red, also have a look through the window to see if something outside is generating it and interfering, be carefull the neighbours dont get people round in white coats though.
I have a cheap import inverter welder for bodging up the landrover, it sometimes turns things off, tv's, the washing machine etc, I doubt its infra red, it'll be rf or mains borne noise.