Yes, there are 2 sets of settings. One for the T245, and another for the T210.
But I doubt it is that.
Mind you, with such a small dial it's difficult to set the temp precisely.
I have the much older AD2700 (internally the same as yours, even same PCB) , which has a larger dial that only goes up to 400C, and even with that extra granularity I cant reallly set the temp to within +-5C.
If bumping the dial a little bit allows you to melt solder, while being bellow the 200C marking, then I say the tip is probably fine.
I lost my t210 handle, so I can't make any tests to confirm until I get a replacement.