The "signal" reading on your receiver is more of a signal "quality" rather than strength..A station can be at full power and not deliver 100% due to transmitter mis-alignment. Or, if the receiver is having to work harder to recover the received signal due to multipath, receive antenna issues, local
interference, etc..the reading will be lower.as well.
It's actually irrelevant if the receiver stays locked and you get solid decoding.
The views expressed here are my own and do not necessarily represent those of ABC, CBS, CW, FOX, MeTv, or AntennaTv; my employer; or its parent company.
Nor my wife for that matter!