Grammarian role taken even though it was already assigned

We had a user (G) assign himself to the Grammarian role for our most recent meeting, occurring November 4th. He assigned himself to this role on November 3rd, around 12:27 PM US Eastern time. I received an email notification for this, as did all club officers.

Later that day, around 6:22 PM US Eastern, another user (S), assigned herself as the Grammarian. I also received a notification for this.
G himself didn't see the re-assignment on the agenda, and was surprised to find out on November 4th that he was no longer the Grammarian.

We didn't receive a notification that G had been unassigned from the role at any time, and I would think that no one should be able to assign themselves to a role if it is already taken (unless they have edit access to the agenda). Could you help us determine what happened here?

I've attached a screenshot of the email thread that shows the assignments for the meeting.

G is our SAA. S is not an officer and has no admin access to agendas.

Thanks,
Tyler - Newport Toastmasters Club 1223

 

Well, when I try to upload the image it's very poor quality. Here's a hotlinked version.

This has always been an issue in FTH that seriously needs to be fixed.
This issue can easily be reproduced with the following sequence of events:

1. Member 1 opens the agenda page.
2. Member 2 opens the agenda page (on a separate device).
3. Member 1 clicks Sign Up as Grammarian (or any other role) on the agenda.
4. Member 2, then clicks Sign Up on the same Grammarian role (WITHOUT refreshing the page - so they didn't see that Member 1 already took the role).
5. Member 2's sign up overrides Member 1's sign up without any warning.

We've seen this happen several times before over the years, including with with Speaker roles. It's very annoying when a member thought they were on the agenda to give a speech, but then we realize their sign up got overwritten by someone else.

The problem needs to be fixed.