Bobs 2014 silverado

On my first trip out side of town my used 2014 Silverado with 40k miles was having cruise control issues. I would engage the cruise and then it would soon disengage. This happened about 3 times bf the power flicked off and then on again but the truck kept operating. Shortly after this when traveling slow in bumper to bumper traffic the truck lost all power. No warning lights or symbols, nothing. I was dead in traffic and so I when to battery area and grabbed both terminals to see if loose but both were tight. I went back in cabin and when talking to AAA the power flicked and came back on. I resumed our trip but did not touch or use the cruise again on our 2 day outing and no more repeat issues. I have since only used the cruise a few short times with no issues. A friend and I did proactively take off both battery connections to they’re old battery and wire brushed and sprayed corrosion inhibitor on the terminals. We did notice some slight white corrosion type material on the ground terminal bf cleaning. It has been several hundred miles since the power loss but my next proactive step is to take the truck back onto the highway using the cruise to see if a repeat incident occurs. If not maybe the issue was fixed with cleaning the terminals. PS- last night I followed the online bloggers suggestion of checking the grounds under the front dash. Both corner grounds appeared to be absent the insulation interference others have suggested so I did nothing to either of the ground posts and just closed the dash back up like it was before. I am hopeful that I fixed the problem by cleaning the batty terminals. I did check with the prior owner of the truck who stated no prior problems occurred for them.