I am experiencing this lately with GSA. I am on a VPS and it's been speed tested so I know it isn't the network.
I start GSA and it runs fine for the first little while then slows down to a minimal number of threads at about 20-30LPM
I was shown a trick to clean up the site lists and that worked for a day and then it started again.
I thought it was my verifications times all being set to the same time but then after I changed that GSA didn't reboot to a better speed again.
I have restarted GSA and my VPS to clear any potential memory issues so I know it isn't that either.
If anyone has any ideas on what I may be doing wrong here I would appreciate it.
I am running good proxies as tested also in case anyone thinks that might be it.
Here it is running 23LPM with 0 threads??? I have no idea what is going on!
I can tell it's not frozen as the submitted continues to rise and CB is answering captchas as well.