Git clone has problem in container

My os is Ubuntu 18.04 and the LXD version is 3.03.
When I create my container and use it, I have some problems.
I want git clone code from bitbucket but I always have this issue in container(container is ubuntu 14.04).

This problem is below:
fatal: The remote end hung up unexpectedly
fatal: early EOF
fatal: index-pack failed

real 1m37.970s
user 0m2.560s
sys 0m0.937s

Sounds like networking issues maybe, could be the MTU doesn’t match that of your physical network or something on your network is killing the connection?

thank your advice.
When i directly git clone from bitbucket without container, the issue disappear.
I only use macchanger tool to change my MAC address, this may cause the problem?
Two container has the same MAC address and git clone from bitbucket at same time.
Will they make this issue?

By the way, could I change the Permanent MAC address with macchanger tool in container?

Current MAC: 00:16:3e:70:74:4c
Permanent MAC: 00:00:00:00:00:00