Blocked from tagging?
Were you using team chat, map chat or squad chat? If you are using map chat it dosnt matter if you are a commander or not. It wont let you do to many messages in a certain period of time. Team chat and squad chat should allow you to message without a limit though. Although to help with communication and call outs its better to do your commanding in squad chat so team chat and map chat is not tied up.
Potion Sella
Sounds right for the spam filter. You can’t link things or say the same message more than 4 times before it locks you out with Say or Map chat. I personally find it annoying if i “typemand” and try to use say chat. I want to use Say to limit my orders to the local zerg and so they can see the chat bubble as an additional indicator of my position.
The best way to deal with this is to type out more orders than simply linking an objective. The more unique your messages are the less likely you’ll get spam blocked.