L2TP over bounding very slow, and link have RX_ERROR ?

I try L2TP and PPTP, and I have RX_ERROR on client ?

all work till I enable bounding on 2 link (one wifi and ether over bullet)

we test link, and we have about 100Mbps (have not problem with bendwith)

when I disable one link (bound work trought another), VPN work fine .

I user RB750

but, another client, with x86 have no problem when we used bouth link.

I think problem are with RB750 ?

any idea ?
l2tp_error.jpg

Hello i have the same problem did you find a solution i hope you can help??