What do you mean sync for first time?
It has synced, it was working and CPU load OK (I had genproclimit=80 to have about 70-80% CPU load) but after block solve it froze.
Could you please try running on less threads temporarily, til we resolve all issues? I think if you are running > 20 threads, its doing a lot of work trying to create the ABNs in the background - and maybe we have discovered that we need to stop a deadlock.
Please reboot, try less threads and also try this:
minersleep=-1
In the config file. See if that rises your proc up to 100%?
Ill work through any others issues and see if we have evidence that solving a block with multiple threads creates a deadlock condition.