I have Rb2011uas connected to the Huawei e3372h-153 LTE modem in the USB port -- lte1 port, 2 channel sfp1 port, these ports are displayed in the interface sheet. When configuring Bonding, the physical LTE(USB) interface cannot be selected - it is not in the list! This is a firmware flaw, or it should be. I'm asking for help.

Maybe because of this ?

Bonding is a technology that allows aggregation of multiple ethernet-like interfaces into a single virtual link, thus getting higher data rates and providing failover

https://help.mikrotik.com/docs/display/ROS/Bonding