You said "many games", how many, roughly? 100s? With how many people? Which game mode in World of Chel? There's no chance that you've played this regularly as you'd have run into this by now, at some point, over the last 2-3 years. As the other poster said, this has been happening for years and it literally makes you hesitant to even change your loadout once you're in your lobby.
I'd say there's roughly a 33% chance this will happen when changing your loadout in the pregame lobby. The video wouldn't show anything. When this issue happens, you're essentially soft locked without the ability to back out of the little UI pop-up that includes "Change Loadout". You can't back up to the screen where you can ready-up. You're forced to leave the lobby, and sometimes you can't even do that.
Steps to reproduce:
1. Go to World Of Chel pregame lobby.
2. Select position.
3. Select Change Loadout.
4. Change something in your loadout.
5. Save Loadout.
6. Change loadout to something else altogether.
7. Press Circle to back out back to the lobby (you'll notice the new loadout has been selected now).
8. Press Circle again so you can Ready Up.
Results: Sometimes/Often, user cannot return to the original state of the pregame lobby where they can ready up. Sometimes/Often, they are stuck with the "Change Loadout" pop-up and nothing works, forcing the user to back out of the lobby as they are locked in this spot.
Note: Steps 3-6 are not necessarily the cause of the issue, this is just the type of stuff you'd naturally do when selecting Change Loadout, and the type of stuff you'd do to naturally stumble into this bug and want to jump out a window.