You can have the track signal driver slowly deteriorate, your symptoms suggest a track signal issue. I've sent several command bases back to Lionel over the years for low signal output.
The late Dale Manquen came up with a simple scheme to measure the relative signal strength of the track signal from the command base. If you wire this up and compare your base with another Legacy base, you can see if you have a low signal strength. You'll need to compare it to a known good command base to verify the readings as they vary based on the meter you use. I added a .01uf capacitor across the meter to stabilize the readings.
