No, the puzzle is between 2^63 and 2^64 BUT:
https://github.com/brichard19/BitCrack/issues/223(uint64_t)_points * _threads * _blocks;
So instead of checking all keys you are basically ignoring alot of keys. If you have e.g. 512 blocks and 1024 threads (doesnt matter if those are valid inputs) you would basically jump over 512*1025 = 2^19 keys.
So thats why you are faster finished.
Yeah not sure where you get your info from. Bitcrack doesn't ignore keys. Unless you are speaking of a bug with the CL version, but the program does not skip/ignore keys unless you use the stride option, on purpose.
Please reread what I wrote: The buggy line results in skipping keys.