I noticed in the screenshot that the text over the Ap and Pe nodes is really far down, almost covering the point on the orbit line.
I recommend increasing the lineHeight variable here:
caption.GetComponent<TMPro.TextMeshProUGUI>().fontSize = 12 * GameSettings.UI_SCALE;
caption.GetComponent<TMPro.TextMeshProUGUI>().lineHeight = 12 * GameSettings.UI_SCALE;
I haven't tried this, but it may help.
I've downloaded your Gitlabs source code and I wanted to build this, but I get errors:
Error CS0246 The type or namespace name 'UnityEngine' could not be found
Error CS0246 The type or namespace name 'KSP' could not be found
So, obviously I'm missing something. Can you point me in the right direction to setting up my VS to create mods? Thanks!