In workspace using advanced work assignment, new chats are not being assigned to certain agents but are being assigned to other agents.
In the logs, this message can be seen indicating that the agents are at capacity.
2019-09-12 05:54:49 (129) glide.awa.assigner.63 SYSTEM 2019-09-12 05:54:49.129 (glide.awa.assigner.63) Assigned 0 out of 1 work items
1 agents skipped:
1 at capacity
The agents have reached capacity for that service channel. The capacity is determined by the filter within the Utilization Condition Field on the service channel record.
To resolve this you just need to edit those records so they no longer meet the capacity filter.