Party Member Check Mark Not Saving

The new (at least to me) option in the character info is a check box if the character is a party member. However, that check mark is not saving and remains off no matter what I do (and I am the GM in the game, so there shouldn't be any problems with character editing rights). Is it bugged or what am I supposed to do with that check box?

Hi Tommi,  What happens when you gather up the group, including the "new" member, and use the right click option for generating the party? Also, what is the exact procedure you are using? Exact step by step would help (every click). 

How I tried it was to open a PC's character info (which has the tabs Character Sheet, Bio & Info, and Attributes & Abilities). Click on Edit and there is a check box under Duplicate, Archive, and Delete buttons which reads "Party Member". I click on that check box, so that a check mark appears in the box, and then click Save Changes. But when I open the character info again, the check mark is gone (even if it should not be). When I right-click a PC's token, I do not get an option to "Add to a Party" or somesuch. There's only "Open Character", "Add Turn" and the rest, but nothing about a party. Is this only for Jumpgate games, perhaps? This game is not, but if it is only for Jumpgate, why does the option and check box appear in the PC info then?

Yes, it is only for Jumpgate. The checkbox shouldn't be in Legacy but perhaps that was an oversight.  Edit: I am not seeing it in Legacy, can you provide a screenshot of where you are seeing it? Please include the entire Roll20 interface in your screenshot.

Here you go.

Ok, I doublechecked and I don't know why I didn't see it initially, perhaps the game was too old.  But I am seeing it in more recent Legacy games. I suspect that is an oversight. It should not be there.