API call on bond_extra does not provide all information

[jonasW3F]

I am currently looking at the bond_extra extrinsic and it comes with a params variable that contains a string with more information of the extrinsic. However, it seems that there is a discrepancy for some extrinsics between the max_additional and the actual value. In many cases they are identical, but in some cases they are not. For example:

Extrinisc#445578-3 shows a value of "0" with a max_additional of "59". The params vector of that extrinsic is:
[{"name":"max_additional","type":"Compact\u003cBalanceOf\u003e","value":"59000000000000"}]. Neither from the params string nor from the other variables of the object can I see how to compute the actual bonded_extra value.