It comes back up at different points. Sometimes it won't even start going down. Both my yellow and green lights are on, but it keeps coming back up.
DO NOT increase the close force. Find out why the close force is suddenly not enough.
How does the door roll manually?
Garage doors are dangerous and can kill you. It's vital to keep their mechanisms tip-top. Problems are easy to detect if you normally operate the door by hand, because you feel the door start to get stiff. (But if 100% of your door usage is via the motor-drive coughEthiopian302*cough*, then you won't know what manual operation normally feels like.)
The motor won't give you a sign of trouble until things are serious. On the upside, this is easier to detect by hand since it's more obvious.
So operate the door by hand. It should roll smoothly and be well balanced. If it hangs up, or drags, figure out why and fix it. Common problem points are rollers getting sloppy (they wobble, or drag: they're easy to check with the door in the vertical position), and dirty tracks.
Do Not Grease Tracks. Putting Grease on them will only attract dirt and dust, creating a nasty filth gumbo that will drag the door even more. Tracks shouldn't need greasing, that's why rollers have ball bearings in them. If you absolutely must "grease" a door, then use graphite paint. This is sold as Lubri-Plate, Slip-Plate, EZ-Slide, etc. in quarts, gallons or spray cans. This dries like paint, and leaves a coating of graphite. You need to shake/stir the daylights out of it, it loves to separate. It won't attract dust/dirt, won't be disgusting on your fingers, and is less likely to ruin clothing.
Does this happen only at some times of day? Direct solar light shining into the sensor can cause false detection. If this is happening try shading the sensor with your body's shadow or another object. If this enables the door to close reliably then consider swapping the sensor and the emitter so that the sensor faces away from the sun, or improve the shading on the sensor. Swapping locations is most effective on a door that runs on a north-south line; if the door runs east-west then swapping locations will exchange the solar troubles from morning to evening or vice-versa (which may still be an improvement if it matches your comings and goings better).
When my garage door opener exhibited similar symptoms, I had to replace a gear inside the box. It was a plastic gear and over the years, it shredded. Open the box and look for plastic shavings. If you find them, examine your gears. One or more of them will probably be badly worn.
Replacing the gear was not difficult. Though, I had to order the gear over the internet as no local shops carried that part.