How old is the battery? First steps measure battery voltage, and perform a load test. In modern vehicles a defective battery sometimes does strange things just like that. That would be the place to begin. Verify battery is serviceable.

Keep in mind the battery voltage alone is an important indication, but a battery can test in the ballpark for the correct voltage across the battery posts, but be unable to supply enough current when put under actual load. Loose or corroded connections at both ends of the cables can cause trouble. Even a paper thin, nearly invisible layer of corrosion is enough. Also be sure to check Owner's Manual for any computer relearn steps to be performed whenever a battery is disconnected or replaced. There's often a routine listed that should be followed.

Batteries do that, sometimes they give a bit of a warning, sometimes not. That's not to say for certain a defective battery is the problem here, necessarily. But it's the first step. Let us know how it works out.

Careful with polarity, and make sure it's not too tall &c, Rangers take a Group size 59 battery iirc.