[CRITICAL] Mission Rewards are not giving to the joining player during Coop gameplay

Platform:
PC/Steam

Description:
[CRITICAL][GLOBAL] Mission rewards are not given to the player that are joining the Host game.

Steps To Reproduce:
Player 1 = Host
Player 2 = Player that join

  1. Have Player 1 start a game
  2. Have Player 2 join Player 1 game
  3. Open Mission Log and track any active mission
  4. Proceed to the location of the mission
  5. Complete most of the objectives
  6. Have Player 2 note the current EXP he has
  7. Have Player 1 complete the last objective in order to complete the mission
  8. Wait for the game to give rewards to Player 1
  9. Notice Player 2 EXP after the mission has been completed

Images / Videos:

Host or Client:
Player 1 the Host which was my Friend.
Player 2 was me which i joined his game after he invited me.

Players in your game:
We were two players: my friend and I.

Specifications:
CPU: i5-8600k
GPU: Nvidia GTX 1080
Ram: 16gb
Storage: 1t SSD

I edited my Original message to match the Bug Report Template.

As per in-game tutorial about MP saves:

With that above, i wouldn’t say there’s an issue with MP missions and XP reward from them. Since when you haven’t progressed enough to be able to do these missions in your solo game, you won’t be rewarded XP from them when you complete them in someone else’s game as a client.

So, if you want XP for the missions, you need to complete them in your solo game.

Though, it does work vice-versa. E.g when you have all the missions completed, you will gain the XP again, if you complete the missions in someone else’s game as a client.
Latter is very helpful in leveling up your 2nd, 3rd and/or 4th char. (That’s how i did mine.)