When I put a figure on a portal, there is a question mark.
just as it is shown here:
Idle figure - TRIGGER HAPPY
Other two figures are defined by a portal normally. What shall I do?
Sorry to hear about your figure!
As that article stated, this most likely is due to a corrupted save on the figure. Have you tried to reset the figure already? For information on how to do this, please see: Activision Support