NTH issue

https://bongda24h.vn/
I have 4 wan and use NTH to get the full speed of wan links and it working great
but in some websites like youtube the viduo stops it self and i have to refresh it every time (i guess cuz its HTTPS)
any help??
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/interface ethernet
set [ find default-name=ether1 ] name=WAN1
set [ find default-name=ether2 ] name=WAN2