The Oxford Dictionary says we can use "complain about something" or "complain of something".
complain: to say that you are annoyed, unhappy or not satisfied about somebody/something
complain about something Shoppers complained about the lack of toilet facilities.
complain of something The defendant complained of intimidation during the investigation.
I remember the difference between "know about" and "know of".
"I know about the machine": I know quite a lot of information about the machine
"I know of the machine": I know quite limited information about the machine
I am not sure if "I complained about the machine" means I complained quite a lot about it, and "I complained of the machine" means I complained just a little bit about it.
We also have the noun "complaint" and we can say "make a complaint about or of something".
ChatGPT answered
The difference between "I complained about the machine" and "I complained of the machine" is that "complained about" is used to express dissatisfaction or annoyance with something or someone, while "complained of" is used to describe a physical symptom or illness. For example, "I complained about the machine because it wasn't working properly" and "I complained of a headache caused by the machine's noise."
I agreed that we can say "I complained of an illness" but CHatGPT tried to avoid my answer because with 1 sense , the dictionary says we can say "complain about/ of something"
I also asked CHatGpt
What is the difference between "I made a complaint about the machine" and "I made a complaint of the machine"?
It answered
The difference between "I made a complaint about the machine" and "I made a complaint of the machine" is similar to the difference between "complained about" and "complained of". "Made a complaint about" is used to express dissatisfaction or annoyance with something or someone, while "made a complaint of" is used to describe a physical symptom or illness.
For example, "I made a complaint about the machine because it wasn't working properly" and "I made a..