As far as I know, the seven-money binary version of Guangxu Yuanbao is common, and the standard weight should be 7.2 grams. However, even the same version of Guangxu Yuanbao may have some fluctuations in its actual weight due to different casting processes and preservation conditions.
According to the information you provided, Guangxu Yuanbao 22.5g obviously exceeds the standard weight of this version. This situation may mean that this Guangxu ingot may be forged, because there is no official record of casting Guangxu ingots with excessive weight.
To sum up, according to the information I have, 22.5 grams of Guangxu Yuanbao is not common, and it may be a fake. In order to ensure the authenticity and value of Guangxu Yuanbao, please consult relevant professionals or auction houses or professional institutions for evaluation. Different versions of Guangxu Yuanbao and different preservation conditions will also have an impact on its value.