The problem is most likely a weak server, plus the wasteland missions are not optimized yet. Try to find a different server.
As servers are operated by users, some of them think they can run a dedicated server on a cheap virtual machine... -.-
I play on Altis on a laptop without issues in multiplayer.

similar to http://feedback.arma3.com/view.php?id=2939

Was about to make same report.

Confirmed for Arma 3 Beta v0.70.106.872

https://dl.dropboxusercontent.com/u/11546627/A3%20Missions/Jesters_Beta_Showcase.Stratis.pbo.7z
In this mission go to green factions hmg car and head shoot the range master in the bunker to experience this issue.

Confirmed for Arma 3 Beta v0.77.109.799

Confirmed for Arma 3 Beta v0.70.106.872

probably configs missing?

also range master related http://feedback.arma3.com/view.php?id=8536

Fixed in Arma 3 Beta v0.70.106.872

The mission mentioned is [SP] Dynamic Whole Map ArmA3 Missions by SaOk
Whole Lotta Stratis WIP
http://forums.bistudio.com/showthread.php?147768-SP-MP-Dynamic-Whole-Map-ArmA3-Missions-by-SaOk

I have the same issue. Player starts as group leader without backpack. After killing a medic or explosives specialist and taking their backpack the backpack disappears with all content when you save and resume from the save.

I have heard from many people about problems with disappearing gear after loading a game save. This is a mission breaker if you put essential gear inside the backpack during game play and save the mission progress to resume later on.

Confirmed for ArmA 3 Alpha v0.56.104.778

Added simple mission to reproduce. Use the second file (pbo) and put it in
C:\Program Files (x86)\Steam\steamapps\common\Arma 3\Missions
Play scenario backpack_test

1 - Kill medic
2 - Take his backpack
3 - Suspend (->autosaves) then resume mission
4 - No backpack

Same with explosives specialist backpack

Confirmed for ArmA 3 Alpha v0.58.105.348

please fix before v1.00 release

Can't imagine a situation when this would be useful.

Switching from main weapon to pistol is only useful in close combat when you have no time to reload.

And if you still wish such functionality you can do it with key combos.

Easy fix: automatically go to closest lower stance with reload animation
Good fix: add reload animations to all stances

There should be an addition to the server browser which shows server hardware performance and server internet connection performance (bandwidth, as ping is not everything).
So when somebody starts up a (dedicated) server a short bechmark should be run and the result should be visible in the server browser for everyone.
You also should be able to filter out low power servers with filters. That way shitty servers won't get any attention and go offline.
Now it is very frustrating for new players as they think it is the game that is horribly optimized and not the low specs servers run by some users.

Adding realistic oxygen/gas mixture usage calculations (for free diving and diving with rebreather) would solve this. Like fuel for cars...
The deeper you dive the more oxygen you use, the more you move the more you use.

@annerajb Sorry I misunderstood your post. We a asking for same feature.

yes change it -> https://www.youtube.com/watch?v=iZTNo6rbEwQ https://www.youtube.com/watch?v=NYvfl-Ylvf0