Critical damage is quadrupled when player manually selects to roll critical damage

Currently the damage dice is automatically doubled after a critical hit. However, if the player right clicks on the damage dice button and selects critical damage, the tooltip shows that it will be double dice, but actually quadruple dice are rolled, doubling the automatically doubled dice. 

Are you by any chance using a third party extension or plugin such as Beyond20 or AboveVTT? I just loaded up a character sheet and rolled some forced and natural critical hit damage rolls and all the dice expressions were correct for me

No, no third party plugins on this browser and clicking straight from dndbeyond. Had a player roll quadruple dice in a game last night and just recreated this myself. Adding a screen recording.

Edit: Embedding didn't work, here's a youtube link - https://youtu.be/X63mIlo8w9g

Edit 2: To be clear, if you roll a critical hit with a d20 and click the damage dice, it works fine. If you simply select critical damage without rolling a d20, it works fine. If you roll a critical hit with a d20 and then right click on the damage dice and manually select critical hit, it will erroneously double the automatically doubled dice and display a tooltip that suggests only the normal doubling will happen (and furthermore falsely shows that only one damage die will be rolled if you select Flat Roll while the automatic doubling will still take place).

DDB allows for many things that do not follow the actual rules.  That option exists so that Champion Fighters (and any other option that extends the crit range) can work.  Also the DM could decide to allow you crit damage or have you roll it for a creature with vulnerability to your damage.  The player just needs to use the tool correctly.  

This is hilarious, the player used the tool "correctly", exactly like it has been functioning in DDB for ages. This has nothing to do with champion fighters, it is a new automation feature clashing with a legacy manual feature. It is clearly not working as intended because when you select critical damage manually it shows you that you will roll two dice when four are actually rolled. This has nothing to do with classes or vulnerability, that is a ridiculous reach.

Quote from ArmorStorm >>

DDB allows for many things that do not follow the actual rules.  That option exists so that Champion Fighters (and any other option that extends the crit range) can work.  Also the DM could decide to allow you crit damage or have you roll it for a creature with vulnerability to your damage.  The player just needs to use the tool correctly.  

 I think you need to read the post/watch the video. OP is reporting that they're selecting the option to roll 2x the number of dice and instead the sheet is rolling 4x. That's got nothing to do with what the DM may allow or any other game rules. It's a bug, plain and simple

Quote from WMoonshadow >>

Edit 2: To be clear, if you roll a critical hit with a d20 and click the damage dice, it works fine. If you simply select critical damage without rolling a d20, it works fine. If you roll a critical hit with a d20 and then right click on the damage dice and manually select critical hit, it will erroneously double the automatically doubled dice and display a tooltip that suggests only the normal doubling will happen (and furthermore falsely shows that only one damage die will be rolled if you select Flat Roll while the automatic doubling will still take place).

 OOoooh, that makes more sense and I can see how that'd trigger.

For a dev, steps to reproduce:

1. Roll the attack dice (d20) until you get a natural 20, triggering the automatic damage dice upgrade to double the usual amount
2. Right click the damage expression button
   • Here you'll see a sub-bug—the popup menu does not display the correct damage expression per the critical hit
     
3. Enable Crit Damage
   
4. Select the roll option at the bottom of the menu
5. Observe the actual damage amount rolled