Changing SMA also changes eccentricity?

[SapphireCarbuncle]

I have an issue where changine the SMA of an orbiting body also changes its eccentricity. An orbit that is circular in one distance will become oblong when it is changed. Locking the eccentricity to zero does not help. Also, changing the eccentricity to 0 also reverts its SMA back to the original value.

EDIT: Currently, Auto Orbit does fix the eccentricity to zero while retaining the current distance, but it's a bit of a hassle to go into two different menus to change a planet's orbit.

[Jar]

I just checked and it looks like those brand new locks we added in 20.7 aren't working properly right now! Sorry for the issue, and thanks for pointing this out. But if I understand your scenario correctly, you can get this to work properly if you make sure Eccentricity is locked and that no other properties are locked (right now the issue is that they can all be locked at the same time).

So set Eccentricity to 0, lock it, unlock Pericenter or the other lockable properties, then change SMA. Hope that helps for now! We'll look into a fix for this.