Game Device Prioritizing seems to be fixed, however upon addressing some issues, they have managed to break (or at least change) some things on the channel selection.
2.4 GHz - Channel Bandwidth seems to be fine, however when selecting a different channel, any net analyzer tool (android or pc) is showing I am on channel 4, regardless what I change this to from the routers GUI.
5 GHz - When manually selecting the channel, the box titled "Auto select channel including DFS channels" no longer unticks by default. Strange one this as all previous f/w's unticked this automatically from experience, when manually selecting channel. My net analyzer is now showing I am on channel 48 when I had set this to 100 in the router.
Interestingly though, I have just manually unticked "Auto select channel including DFS channels" in the 5GHz menu and now I am showing to the be on the correct 2.4GHz channel via the analyzer. Unfortunately, in doing so, I am now showing to be on channel 36 on the 5GHz band, when in fact the routers GUI shows 100.
Just as I thought progress was being made.