What shall I do when water levels in the soil are unequal? Thanks.

In a pot, the water levels in the soil will always be un-equal - that's the nature of a pot. Its called a perched water table, in this case, the "perch" is the bottom of the pot. If you cut the bottom off the pot, the problem will go away but that's not practical if you want to grow a plant in a pot.

When you first put a plant into a pot, the rootball doesn't reach the bottom or sides of the pot. Do you know where most of the roots are now? If its a plant that appreciates moisture, probably in the bottom part of the pot. If its a plant that likes drier conditions, in the top part of the pot. The roots won't grow where conditions are uncomfortable. Knowing where the water levels are and what moisture level a plant needs are the only way to figure out when to water.

The pot in your photo is a fiber pot so the sides always be drier than the middle of the pot.

I hope this helps.

What DaisyI said:)

I've never used a fiber pot before.

When in doubt I tend to soak and drain well.

Not familiar with fiber pots so not recommending that, but my first impression looking at the photo was that was a root-bound plant out of its plastic pot!

When in doubt water slowly in small amounts, give it more time to saturate keeping in mind that dry soil can repel water at first.