When playing multiplayer, (I think) you only gain experience if the lobby doesnt only contain players from your IP adress / LAN.
No clue what I answered to in below text…
In AoE 3, there exist 2 or 3 different savefiles for Exp as a Home City grows through gameplay.
One is ‘Multiplayer’;
playing LAN does not count as multiplayer.
The second is ‘Lan’
A potential 3rd (if not same as LAN is ‘Campaign’.
There is something called ‘Skirmish’, I am pretty sure it counts with LAN.
When playing AoE3 LAN, the Home City level doesnt update until you enter the Home City Window, preferably, you could change some deck and/or add some card. Now Exit and restart AoE3.
You should only need to do this one time, then the gamefiles should be found easier for the computer.
- Out of Sync Error -
Is often caused by some error of information between the two computers.
So check the LAN connection, including firewall in computer,
approvance of program to operate,
firewall of Router/Modem,
Typically its the firewall or some bug with incoming phonecalls ending the connection ;(
Hopefully, someone else has some better input