"Unable to find the object Sys.Browser("chrome")" When Running Several Back to Back Tests

I can reproduce the error using your code,

I suggest you keep your coding simple,

Ideally, it's best to close all browsers first, then launch your desired browser to perform the necessary web app testing.

The code that's within a function, should be indented and no need for the extra line after the opening bracket - it makes the code easier to read.

Also, ensure you are using a "working" version of TC. I find that v15.55.53.7 is stable.