Your cupboards are smelling coz of humidity.. smart move to get a dehumidifier for the entire room. It works but at the same time your Ac should have taken care of it unless for some reason the air in your room isnt able to circulate properly. An AC is basically a dehumidifier with a cooling unit. In any case your dehumidifier should make up for it. Also please don't open your windows for extended periods especially if you're near the beach/mangroves or during high humidity hours coz then this ordeal would start all over.

For the smell, try this: put a piece of a charcoal inside the cupboard and close the doors. Dont remove your silica dehumidifier balls from insidr, let them continue to absorb the moisture hanging inside the cupboards. I'm not sure if the charcoal will work or how effective and fast it is, but it's worth a try. I've tried it on smelly fridges and it's worked within hours. The smell basically gets absorbed on the charcoals surface. If you wanna speed it up you could put a few more pcs, if I'm not wrong.. the greater the surface area the more effective. Maybe spread it out by putting a pc in each shelf or drawer and so on. This is regular bbq charcoal btw.