Safe checks
Turn the controller to off and see if the wet spot stops. If it stops, the water is irrigation, not a constant supply leak. Lift the lid of the valve box only if you know where it is, and do not stick a hand into a box you cannot see. At the clock, confirm the time and that the rain sensor is not parked on skip.
Leave the glue alone
Cutting a lateral and cementing a coupling is how a small leak becomes a longer one, especially if the line is still under pressure. We shut the zone down, find both ends of the bad section, and test the station after the repair. Call 346-642-6161 rather than opening a trench from a photo.