I'm now aware of this. Some of this is a known issue by Xenforo, and is related to the editor that they are using. I'll be working with Mike over the next quarter to upgrade Xenforo to the latest versions and see if we can roll some fixes.
Please understand that an upgrade to Xenforo for us is not a simple point and click and upgrade, so we just don't upgrade for the sake of it unless there is a critical security issue etc. There is extensive testing that we have to do because of our custom account management integrations, so all I can suggest at this point is to be patient. Very patient.
One solution is to disable the advanced editor for mobile users, but that there involves possibly impacting and confusing all the people that aren't experiencing this issue. So it's balance that we're looking at.