Water runs straight through the pot

Water leaving the drainage hole immediately does not always mean the plant has had enough. Sometimes it has found an easy route around dry material.

Is the middle actually wet?

Check the root ball carefully. Dry medium may shrink away from the sides or resist absorbing water. Dense circling roots can also leave little useful medium in the container. Compare what you see with the plant's recent history.

What can you try first?

Apply water slowly in separate passes, allowing absorption between them. If the species and container are suitable, a short monitored soak from below may help rewet a dry root ball. Remove the pot and let it drain; do not leave it indefinitely in deep water.

When is repotting the better answer?

If roots tightly fill the container or the medium has deteriorated, repeated soaking may only manage the symptom. Assess the need for a suitable new pot and fresh mix.

Do not assume all fast drainage is bad. An appropriately open mix can drain promptly after becoming evenly moist. The distinction is whether water reaches the roots and remains there in a form and amount the plant can use. Verify that condition before deciding that either more water or a denser medium is required.