I've found the issue- there's a custom Logger that got somehow chained into this component (I assume through the NGXSLoggerPlugin) that I didn't know about before (it's a big codebase and I'm relatively new to the team). Once that was appropriately mocked, the tests worked fine. I've updated the code in my question to comment out/in the code that I'm using currently, in case anyone else is looking for tips on mocking NGXS Store functions.