Slitherine

Playing campaign on easy level. Upper left shows I have supply of 13. I have seven combat units and three individuals (son, sister, and troll). That's 10. I have plenty of money (over 300) and two weapons. But my supply level says 13/13. Therefore the game won't let me add any more units. Yes, I owned a settlement.

I also tried to add a unit between battles when I had supply of 11 and my army was brother, sister, and seven units (that's 9) Still wouldn't let me buy new units.

One last thing I noticed … as I entered the battle upper left said supply was 11/11 (but I only had the 2 and 7). During the battle I explored a cave and was rewarded with two additional supply. Upper left then read 13/13.

Any idea what is happening?

Trolls and heroes count for two supplies and you have probably received a troll ally in that cave.

That explains it. Thanks a bunch.