Single Zone has Little Pressure, New Problem
If the sprinkler controller can cause that zone to start dribbling then the solenoid is fine. (Note that "solenoid" is just one part of a complete valve.)

Do an experiment to figure out whether you have a broken pipe or a malfunctioning valve. For example, turn on one working zone, then (at the same time) turn on another working zone. (You may have to operate the valves manually rather than using the timer/controller.) Notice how much the spray of the first zone drops when the second zone comes on. Turn off that second zone, and while the first continues to run, turn on the malfunctioning zone. Does the spray of the first zone drop again? If it does then water in your malfunctioning zone is going somewhere, but not out the heads -- you'll have to locate and repair a broken pipe. But if the spray level of the first zone does not drop, then the valve of the malfunctioning zone is not opening as it should.

If you conclude the valve is malfunctioning there's a chance it could be caused by debris (a grain of sand, a small weed seed, etc) lodged inside. This could happen even on a drinking water system, but it's less likely.

I suggest that you consider how you would go about replacing that valve, have the required supplies on hand, and then try carefully disassembling the existing valve. Start by fully unscrewing the solenoid, and if there's no debris found there, take off the top of the valve. After cleaning it out, reassemble and test.

If things go well the valve could work normally again. If things go badly.. you're already prepared to replace the valve, so go ahead and do that.