Over the passed 6 months my keyless entry has slowly become less sensitive to the point it no longer works. I cannot lock my car. The batteries have recently been replaced in my main fob. They test 3.04 volts each. The spare fob batteries are original and are 2.95 volts each. I am the sole driver so only one fob is used. Using my spare key fob makes no difference. I bought the car new 19 years ago (2006 B200). This is the first time I've had door locking problems other than changing the main key fob batteries.
Any ideas on resolving my problem?