There is no shortage of mis-information on the 'net about dielectric grease. People think
"hmmm, dielectric means it won't conduct, why should I put a layer of something that doesn't conduct in between my connectors? That would seemingly just prevent conductivity. Boy, that's really dumb." But that's not how it works. I've seen a zillion industry tech sheets that call for dielectric grease on connectors, both low voltage and high voltage. And, as the gold test, I think ERA put a dab of it on just about every connector I've monkeyed with. And God knows I've monkeyed with most of them....