ODBC Stops syncing (MSSQL)

[Zablab]

Info:
We've got a couple of MSSQL Servers we'd like to monitor & I'm using the "MSSQL by ODBC" Template. I'm currently only testing our Primary.
I've tried using various Drivers, including SQL ODBC 17, 18 & FreeTDS.
The SQL Server has roughly 200 Databases on it. It's a physical box with robust hardware, memory\cpu\disk shows no immediate out-of-the-ordinary usage.

Problem:
The initial sync pulls in Data but then stops working if any of the Discovery rules are enabled.
If the Discovery rules are disabled, the regular Items like primary PerfCounter works fine.

I've tried to enable just basic Database Discovery, and even disabled most of the items, so it's only down to things such as Database state, DB size & Log size
I'm not sure if it's hung. Can't find anything in logs indicating what the issue is, it just stops pulling Data even if I send a manual execution.
If I disable all of the Discovery rules & restart the Zabbix-Server it starts working again, in terms of pulling basic PerfCounters.
I've tried upping ODBC Pollers which doesn't seem to make a difference.

[Zablab]

Update & additional info:

We're on Zabbix 6.2.2 on Ubuntu 20.xx (recently upgraded and issue persists)

I've installed unixODBC 2.3.7 Driver, and I've tried using various Connectors:

[ODBC Driver 18 for SQL Server]

[ODBC Driver 17 for SQL Server]

[FreeTDS]

It just seems once the initial LLD pulls Data the primary Zabbix-Server Collectors stop functioning. I need to restart Zabbix-Server in order for things to start collecting again.

I don't see any errors in the Zabbix-Server or Agent log to help steer me in the right direction.

CPU & Memory Utilization doesn't surpass 50% while this is happening so it doesn't seem to be related to Hardware performance.

There are a couple blips in overall Zabbix performance\Metric collection that indicate something is tripping up but unsure why.