Remote control overlaps with another device after resoldering

Hello everyone.

I have a StarSat receiver and a DTV receiver in my home.

The StarSat remote control had some problems that I had to hit it several times to get it work so I decided to open and resolder it. I did this and closed its case with some pressure, then I went to check if it works, and it worked fine with the StarSat receiver but the problem is that some of the buttons on the remote control, works on the DTV receiver!! For example “button 5” on the StarSat remote control, does “mute" the DTV receiver :| I really doubt that it was like this before :/

Is it even possible that this thing happened just after I opened and resoldered it or was it like this for 3 years and I hadn't noticed?!! If so, then what's the problem and how to fix? Thanks in advance