Strange upload problem

maybe someone can help me with a very strange problem
I’m using a mhp with a usb modem
just ppp-out , no other setting at all
when I run speed test - I get download 40Mbps
but when he get to the upload I get 0 -
I have try sevral servers to check - all of them Iget the same problem
I have change the modem (MC7304 - MC7700 - MC8790 ) with all of them I don’t get any upload

what could be the problem ?

# feb/14/2018 12:02:42 by RouterOS 6.41.2
# software id = YAAQ-G5ZZ
#
# model = 951Ui-2nD
# serial number = 7C26071C1111
/ip pool
add name=dhcp_pool0 ranges=10.0.0.2-10.0.0.254
/ip dhcp-server
add address-pool=dhcp_pool0 disabled=no interface=ether1 name=dhcp1
/port
set 0 name=usb1
/interface ppp-client
add allow=pap,chap apn=internet.pelephone.net.il data-channel=2 dial-on-demand=\
    no disabled=no info-channel=2 name=ppp-out1 password=pcl phone=*99# port=\
    usb1 user=pcl@3g
/ip address
add address=10.0.0.1/24 interface=ether1 network=10.0.0.0
/ip dhcp-server network
add address=10.0.0.0/24 gateway=10.0.0.1
/ip firewall nat
add action=masquerade chain=srcnat
/system identity
set name=4GRouter
/system routerboard settings
set init-delay=2s

Thanks ,

Hi

Update your masquerade rule to only masq traffic leaving over your ppp interface.

Also have a look at: https://wiki.mikrotik.com/wiki/Manual:Securing_Your_Router