Antenna reception diminishes after initial channel search

I get this too, especially if I run an autoscan right at sundown. At sundown i get all sorts of stations that disappear shortly after.

My laptop power supply knocks out a very strong channel whether I use the DC to DC or the AC to DC, but the AC to DC also requires the inverter which causes more rfi. Some LED's knock out some other channels.

I try and use some Deoxit d5 every so often on the f Connectors, especially those outside. Sometimes it helps ither times it does not.