I did it again and it worked. Took some time on the step of demolishing old network components (forgot two end-dots and it took me a few minutes to see that; the game does not hint you were the dots are, it just points to some desert place somewhere between the dots); water pipes went all right this time, so it was possible something odd, yesterday. thanx for your tip!
No problem

Yeah the cable demolishing is a bit weird if you are not used to it.
One more tip that might be a bit misrepresented in the tutorial: You can theoretically manage "outposts" with a RC transport, but it's very micro-heavy and I would not recommend it.
It's better to use a drone network, i.e. drone hubs with areas that overlap on at least one universal depot, until you have shuttles, and then do long-distance expansion.
Choosing the commander profile "rocket scientist" gives you shuttle tech from the start and can really make things easier in this regard when you are not yet that experienced.
Another thing that I think is generally underrated for new players: Rare metal depots and the cash you get from them are the initial lifeblood of your colony. Try to build your first dome at or at least near a rare metal deport. I usually pick 5+ probes in my initial rocket to be able to scout a good starting location.
Lastly, I can only recommend
this guide for new players if you want to read a little. Good luck with your colony
