Remote control devices use infrared to communicate with the TV/HiFi/Set top box etc.
In general they have a high level of immunity from general background interference – but a second IR device in transmit mode will more often than not scramble the signal. The only other source of interference is likely to be IR lights used on security cameras getting into your room.
First, I would locate the receiver cell on the TV, normally it appears as a frosted plastic insert or other clear plastic insert somewhere on the front surround of the TV – its location may be given in the instructions for use. Then check that there is nothing blocking the line-of-sight between the remote and this location on the TV.
Besides checking that you have fresh batteries in the remote – it might be worth considering purchasing a universal remote control to replace the one supplied.
I did just that on our main TV in the living room. The remote supplied was very temperamental and required precise aim to communicate with the TV. But we only change channels/switch off/on control volume using the remote – you are unlikely to find a universal remote control that will allow you to access the plethora of functions on modern digital sets.