The problem is not with MG2 but with the Tascam 2x2 which, for all I know, does not have a multi-client asio driver, meaning it can only use one asio application at a time.
The first asio application loaded will take precedence and prevents the others from using the asio driver.
This is the reason I parted ways with my Steinberg audio interface and switched to an RME that can use multiple asio applications simultaneously, i.e.multiple MG2 standalone instances and others asio apps.
However, you will be able to use MG2 plugin in Studio One or any daw or plugin host without any problem.