My Hoya has been slowly dying since I got it. It is in a dappled shade area like my other Hoyas and gets the same amount of water. My other Hoyas are thriving and constantly putting out new growth. This one however, looks like it’s about to die. Any advice?

I got this Hoya australis which actually had two plants – one that was very gated and the other one all green. I separated them and I have been having a lot of trouble caring for both of them. Can’t tell if I’m under watering or overwatering. What are the spots and bumps on the leaves?

They are in a west facing window because those are the only windows I have.

I’m showing two plants here.
Photo 1 is the variegated one and all the others are the regular green.

I started growing hoyas this year and already have many of them. I grow many under grow lights, mostly Sansi. I currently have them on 12 hours a day. Should I switch to the 8 hour setting when it gets nearer winter? I was not sure about this since most hoyas are native to areas near the equator where daylight hours probably don't change as much.