Rm551e-gl openwrt best settings

Good morning, I installed the great Romulan custom ROM in the module, using a M.2 to ethernet adapter. I’ve big difficulties in openwrt settings. I have problems with IPV6 ULA prefix and very slow download speed and I have every time to flag band 78 in quecmanager because I find it disconnected. My knowledge of openwrt is very very limited. Could someone help me? Thanks and regards

Dear @minkows
Sorry, we don’t have more experience for openwrt.
Hope other guys form forum will help you.