I agree with Lin and Peggy, I definitely want to know what your soil and watering routine are like. In my plant groups on FB, incorrect soil and/or overwatering are the top causes of hoya problems, by far.
In my experience, hoyas' need for humidity is overrated. They may like it, sure, but it's by no means a necessity, at least not for the common varieties. My household humidity averages 30-40%. I have my Bella on a pebble tray that I forget to fill half the time and the Carnosa has never gotten any help at all. They're both thriving.
So I'd lose the humidifier for now, or at least move it to another corner where it can humidify the room and not the plant. And stop moving the plant around! Its light processing, dry-out rate and water usage are different when it's in the sun vs not, and it needs to be allowed to get used to one set of conditions to be happiest. So pick one and leave it!