What to Investigate to Determine Cause of Inability to Connect

I support an ERP system named Epicor Prophet 21 at a mid-sized company. Every few months we experience a system outage and it is due to SQL Server no longer accepting connections. The connection attempts all time out. The Windows Server host CPU, RAM, Network levels all look quite normal. We have found that the only way to resolve this is to reboot the Windows Server host. We're running Microsoft SQL Server 2019 (RTM-CU30) (KB5049235) - 15.0.4415.2 (X64). It is hosted in a VMWare environment. VMWare Admins insist that there is nothing wrong in the hypervisor and I believe that is the case. Before rebooting, I reviewed logs in the Windows Event Viewer. There are hundreds of instances of, "A time out occurred while waiting to optimize the query. Rerun the query." What can I investigate within the SQL engine to learn more about what causes this condition that leaves the SQL engine unable to accept new connections? My first thought is that we must be exceeding the number of max connections and the only way I can think of for that to happen is if connections are created and never destroyed.