Yes, it's a known issue.
It will currently happen with any debugger, as this is actually caused by the compiler.
In order for a debugger to work, the compiler adds "debug info", which among other things, describes all variables.
FPC identifies "currency" as an integer type. (IIRC 8byte signed int).
That is also how fpc actually compiles this. Currency is stored as int, not as float. The value stored is multiplied by 1000. Allowing for precisely 3 digits after the decimal dot. Because it is not stored as fraction, there is no rounding error (which is important for currency data).
Internally FPC makes sure that the data is correctly handled and displayed.
But it does not include this info for the debugger.
Currently the only difference between the types Int64 and Currency is the name.
But, the debugger can not rely on this. Since any one can define their own type currency "type Currency = int64;" and that would then NOT be a currency....