support response:
This is an expected behavior on RB3011 because inserting/removing of SFP module changes internal connection allocation to use the spare 1Gbit connection to the CPU. https://i.mt.lv/routerboard/files/RB301 ... 123613.png
same high ping problem in version 6.8 rc1please redownload the v6.8rc1 package from the link above as we have made a new test build with some fixes for ppp module.