Have you had your soil tested?
What did you do to amend the soil?
Is this a raised bed or on the level ground?
Did you do a drainage test?
Is this garden in full sun?
Fungal dominated soils usually have a pH that is not ideal for many plants.
Soils that are constantly wet or poorly drained do not support many kinds of plants there is not enough air around the roots and if you have phythopthora in the soil, it would be difficult to grow plants in ground.
https://pnwhandbooks.org/plantdisease/pa ... a-diseas-1
Your soil mix should be 1/3 soil, 1/3 compost, 1/3 (perlite, vermiculite, sand, cinder for drainage).
If you are growing mostly in compost, it can hold too much water. You may be watering too much. You should be watering only as needed. The surface will dry out but if the soil is still moist when you poke your finger in the soil a couple of inches down wait until it is almost dry.
Since you have had problems with plants in this location, try a different location. Make sure you do not bring any plants from this location to the new one. Clean off all tools, shoes, hoses, gloves in a 10% bleach solution to avoid contamination.
Select a site in full sun, on high ground where water does not puddle or collect. A raised bed may be better. I would use 1/3 peat moss, 1/3 perlite, 1/3 compost in the mix.
Happy gardening in Hawaii. Gardens are where people grow.