two intermt coonections for one username

hello!
i have two mt rb1100ah
mt1 have two real ip on two interfaces. mt2 have one real ip.
i need create two separate l2tp tunnel from mt2 to mt1.

mt1:

/interface l2tp-server server
set authentication=mschap2 default-profile=l2tp-server enabled=yes

/interface l2tp-server
add name=l2tp-xxx user=xxx@yyy
add name=l2tp-xxx-02 user=xxx@yyy

/ppp profile
add change-tcp-mss=yes comment="encription required" dns-server=\
    10.0.1.50,10.0.1.51 local-address=10.0.5.1 name=l2tp-server only-one=no \
    remote-address="vpn clients" use-encryption=required

mt2:

/ppp profile
add change-tcp-mss=yes comment="encription required" dns-server=\
    10.0.1.50,10.0.1.51 name=l2tp only-one=no use-encryption=required

/interface l2tp-client
add allow=mschap2 connect-to=extip1 disabled=no name=l2tp-tn password=\
    "qq" profile=l2tp user=xxx@yyy
add allow=mschap2 connect-to=extip2 disabled=no name=l2tp-da password=\
    "qq" profile=l2tp user=xxx@yyy

if one of two tunnels enabled - work good
if two of two tunnels enabled - disable each other by turns

how to resolve problem? i need two tunnels for redundanсy.

Why not use two different user names, one for each connection?

look at Logs for the reason of disconnect