Most microwaves have a spinning wave stirrer in addition to the rotating plate. From the description here, it just sounds like either your plate rotation motor is broken or you’ve got a weirdly simple microwave.
Usually it’s not inside the same chamber as the food as then it would be a nuisance to clean. You need to take a microwave apart to see the wave stirrer.
Most microwaves have a spinning wave stirrer in addition to the rotating plate. From the description here, it just sounds like either your plate rotation motor is broken or you’ve got a weirdly simple microwave.
This is the first time I’ve heard that they have a wave stirrer. I’ve never seen one in person.
Usually it’s not inside the same chamber as the food as then it would be a nuisance to clean. You need to take a microwave apart to see the wave stirrer.
But maybe don’t take apart a microwave unless you absolutely know what you are doing. Otherwise, what you find may be shocking.
Weirdly simple. It does not have a rotation motor. It is quite old.