Where did you downloaded that portable Electrum?
From electrum.org, double checked from my browsing history.
Do the original wallet's bitcoin addresses starts with "3", "1" or "bc1"?
It starts with 1
Do the newly restored wallet's addresses start with the same character?
Yes, all of the addresses start with 1
Also, double check on any blockexplorer if the addresses with balance reflect the same transactions as your "inbound" transactions.
I have only used the address for receiving fund, never tried to send before. Also the address with fund is the only address I used from that wallet.
There is no weird transaction as far as I am concern.
Works just fine, definitely not a bug of Electrum Version 3.1.3 Portable.
If there was such a big issue with that version of client it would have already known by many, but I am thinking there might be some specific condition of my computer which triggered this problem.
I have verified the exe I downloaded, so it is basically impossible for me to use an infected client, it is also hard to interpret wallet creation process.