Bugs or my misunderstanding the rules?

[threegreens]

I am on my third solo game with one automa. Two strange things I don't understand.

1. I sometimes am not given the option to use management actions although some spots are free and I have enough engineers. The heading says "take construction with x engineers" instead of "you must place an engineer" and I am only allowed to construct. Restarting turn does not help.

2. Tried several times to construct a conduit (lower left, value 3) but was not allowed although I had more than 2x3 excavators.

Thanks for helping a novice.

[threegreens]

DISREGARD no.1
I may have miscounted my credits.

No.2 is still unexplained.

[T72on1]

Hard to tell like this, without looking through the entire replay of the game.

Did you have a tile availble which would allow you to build a conduit? Did you have enough engineers to take the build action?