One way to guess whether over-watering (or under-watering) is a problem is to check the weight of the pot before and after watering.
if the pot never gets relatively light, maybe it is holding more water than is good for the root hairs. They will run low on oxygen if the mix in the pot is too fine and too wet. Water displaces air from small and medium-sized pores in the soilless mix, then CO2 can't diffuse out and O2 can't diffuse in fast enough. Root hairs start to drown, and the plant may look like it has too little water.
It's good to know how heavy or light the pot is when it is pretty dry. You can remove much of the excess water from a pot with fine, water-retaining mix by setting the pot down on a folded-over towel. The towel has to TOUCH the soil mix through the holes int he bottom.
If the towel gets soggy-sopping, you can wring it out and continue draining water, or drape one end of the towel DOWN so it dangles BELOW the bottom of the pot. Water will flow from the pot to the towel, then DOWN and drip away, so more water can drain from the pot.
If the towel became sopping, listen closely to see if you can hear the root hairs giving thanks as a little oxygen reaches them for the first time in days!
Another test is to try to gently ease the root ball out of the pot far enough to see whether the "root ball" is a dense-packed, root-bound mass of coarse white roots. If it is, you may need to pot up to a bigger pot), or even do some root-pruning IF Umbrella Tree is something that can take root pruning.
But ask someone who knows them well before root pruning! A photo of the root ball would be informative.
If you try to see the root ball, and you don't find many roots, it MIGHT have a serious case of root-rot.
