Craft orbit messed up

[Alpaca Z]

I launched a space station into a 75 km orbit around Kerbin.

Then I tried to launch a spaceplane to dock with it.

Somehow the orbit of the station got messed up after the plane got to orbit. It got into the atmosphere and would crash into Kerbin. 

Here are the screenshots.

https://imgur.com/a/O7xExh3

Edit: I just noticed that the engine on the station is somehow firing when I switched to it. That seems to mess up its orbit. But the engine was off in a save before the launch of the spaceplane.

I have no idea why it would turn on.

Edited February 27, 2023 by Alpaca Z