I know the format for the YM e-mini for IB is:
YM^^^MAR^21-ECBOT-FUT (where each ^ is a space)
Using ECBOT-FUT-USD on the end part will also work.
But to get the micro contract, I was expecting this to work:
MYM^^^MAR^21-ECBOT-FUT-USD (also tried this)
The IB plugin is reporting that this symbol is invalid. I have no trouble getting the MES, M2K and MNQ micro contracts (different symbol format, of course).
I'm using 6.39.0.
Thanks for showing me the error of my ways.