The thought comes to mind that something is going on with the roots. Either it was overwatered before you received it and some of the roots rotted so are not able to support the top growth, or what is more likely soil it was originally planted in before you repotted it had become so dry it resisted the water you gave it and just ran off down the sides.

Poke your finger into the soil close to the base of the plant and see it is is damp. If dry perhaps it is warm enough to take outside for a couple of hours and water it from a hose at a slow trickle until the soil around the root ball is rehydrated, or set it in the bathtub with a slow trickle from the faucet.

If the soil IS wet deep down around the root ball let us know and we'll go from there. Good luck.