Harvesting Issue. Can't seem to harvest anything anymore. Account IS active

[NanaLelyakova]

I have 160k plus VESTED right now. I haven't harvested anything from any blocks since block 1128498. We are now in 1173697. I HAVE harvested XEM in the past.
My remote status shows as active on both the wallet and blockchain explorer. The thing I don't get is the node I'm supposed to work off of. Seems that everything from the top down says "no slots - choose another node". Sometimes I'll select a node then a few days later i get the "no free slots" message again.
Maybe I don't understand how to choose a node? Do I have to click any of those buttons to the right of the drop down?