I have an identical problem and is currently working with Support. I am glad I was able to find this post with corresponding bug ID. In meantime, I was able to come up with workaround.
So, it looks like the Ucs_save process does not complete correctly at some point, staying active on the system. That in terms prevents any concurrent ucs_save jobs from running. As the pile of ucs jobs grows bigger syscalld seems to go out of control excessively consuming resources.
So, if you run
ps aux |grep ucs
you should be able identify running ucs_joubs... you might see a bunch of them. Identify the oldest one. That should be the one that is hang up. Kill it by executing
kill -9
Restart "syscalld" by executin:
bigstart restart syscalld