looks like the esc is still a castle sidewinder, but "waterproof" and rebranded.
It's probably one of these
. Probably the same instructions for calibration (see section 14 of this
It's sensorless so it will cog sometimes. It will cog badly if the drivetrain isn't free or if it's geared with too low of a FDR
If the ESC is calibrated to the radio, then the most likely culprit would be that the bullet connectors going into the ESC are not making good contact
. Give each of the wires a little twist to turn the connector in the cup. Then try giving it a little throttle. If one is loose you can pry it open a little with a knife
If not, then check for some thing caught under the rear diff, too tight of a gear mesh, the belts rubbing on the motor or your battery or maybe a seized bearing.