That's interesting. It's due to the fact that we only have 8 decimal places of accuracy.
/** Amount in satoshis (Can be negative) */
typedef int64_t CAmount;
/** The amount of satoshis in one BTC. */
static constexpr CAmount COIN = 100000000;
CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)
{
int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
// Force block reward to zero when right shift is undefined.
if (halvings >= 64)
return 0;
CAmount nSubsidy = 50 * COIN;
// Subsidy is cut in half every 210,000 blocks which will occur approximately every 4 years.
nSubsidy >>= halvings;
return nSubsidy;
}