Why Do I Only See One Character?

Hello, Fellow Game Planers... or whatever we call ourselves!

I accepted an Invite into a new game, and I'm excited to play. However, when I look at the Submit Character drop-down field, it only shows me one character to choose from. Where I'm confused is that for this game style, I actually have 4 characters. Why is it only limiting me to choosing one of them? I cannot see any obvious or overt differences between the one I can see and the other 3 I cannot. Obviously, I can only select ONE character to play with- I get that- but I should have four to choose from, yet I don't.

Any help available? I'm sure the solution is simple, but it eludes me. Screenshots below:

Game is D&D 3.5 and only lets me choose one character, Merryweather:



Yet looking at my character list, I have a total of four (4) characters created with that ruleset:



Why is it only letting me choose Merryweather?

Are the other characters in games? Are they using different character sheets?

To expand on cowley's answer, you can only submit characters that use the same sheet style that the GM allows, and the character can't be in any other games. So for example you can't submit a Cthulhu character to a 5e game.

The variation in rulesets makes sense; a 5E character won't appear in the list for a 3.5 game. That's why I listed those characters I have which are under the 3/3.5 ruleset. I have many others with different rulesets that don't come up- and understandably so.

[b]AHA! Yes. All but Marryweather are in other games. Are you only able to use a character in one game?

If that's the case... and I think you may have found the detail... is there a way to copy an existing character? i.e. if I want to play the same character in another game?

I think if you copy the code for the full character sheet into a new character (replacing anything there) you can copy the entirety of a filled out sheet. When you go to the character use the pen(cil) icon at the top to get the code rather than the sheet.