Both of my giants as well as others I have seen in photos do this. They always get stuck doing this little dance and they never seem to get fully flowing.
My red/clear giant did this as well. I filtered it a few times becuase it was cloudy and it seemed to work for a while until it clouded up again. I think I filtered that globe 3 times at least and then I just gave up on it because the flow stayed the same and it still clouded up. I think the lava was shot (most red wax lamps tend to do this). Maybe try filtering it and see if that helps the flow. Looks like it could use a little filtering. If that doesn't work try a bulb extender to jack the heat up some.
I took the above photo after it had been on for 24 hours. It does this the entire time, even 4 hours in. I put a fan on the top of the lamp hoping it would cool the liquid at the top and make the wax rise but that didnt work either. I really do not want to have to open the lamp because I cannot get the cap to fully close without it leaking.