Select Hero screen shows one of the Heroes that is already taken as an option, can potentially be used to lock games in loading screens

Issue Type (Required):

Exploits

Issue Description (Required):

Select Hero screen sometimes shows one of the Heroes that is already taken as an option (for games where there are already 3 out of 4 players, the chance might be as high as 50%), clicking ‘Confirm’ on that Hero will reset the 20 sec timer, you can keep doing it forever to take up a slot or delay loading in between rounds.

Steps to Reproduce (Required):

Quickplay into a match with a Hero that is already taken.
I was already a Bounty Hunter, but the Hero select screen showed 2/5 options, Saltzpyre and Kruber
I click ‘Confirm’ on Bounty Hunter and it reset the 20 sec timer given to choose a hero.
I was able to keep doing this for minutes, but eventually picked Kruber just to see, indeed Saltzpyre was taken as Warrior Priest, and nobody in the game was Sienna, but she was not even an option on the Hero select.
Because you are still in the keep, this can be exploited to hold up a slot without joining the game, and if this happens between rounds it will likely lock all other players in a black loading screen. (game usually waits for everyone to load in at this point)
Biggest issue is that we’ve had a game before where one guy joined one of our games during a load screen, and the game was stuck on a black screen for over 5 minutes, eventually it loaded but that player was not in the game anymore, so probably he had this happen, spammed select on his own hero, and then gave up, never even joining the game.

Reproduction Rate (Required):

Common (<50%)