I run the script on your account and found 3 duplicate entries:
{'producer': 'themarkymark', 'vesting_shares': {'amount': '487047858', 'precision': 6, 'nai': '@@000000037'}, 'trx_id': '0000000000000000000000000000000000000000', 'block': 42304342, 'trx_in_block': 4294967295, 'op_in_trx': 0, 'virtual_op': 1, 'timestamp': '2020-04-06T13:01:27', 'account': 'themarkymark', 'type': 'producer_reward', '_id': '5efd96c86758e62daab6251b4fd40e286ab6f3c2', 'index': 2411563}
{'producer': 'themarkymark', 'vesting_shares': {'amount': '487047842', 'precision': 6, 'nai': '@@000000037'}, 'trx_id': '0000000000000000000000000000000000000000', 'block': 42304354, 'trx_in_block': 4294967295, 'op_in_trx': 0, 'virtual_op': 1, 'timestamp': '2020-04-06T13:02:03', 'account': 'themarkymark', 'type': 'producer_reward', '_id': 'fa4ff605eaec77ec4949b475fba30f5372c70d69', 'index': 2411564}
{'producer': 'themarkymark', 'vesting_shares': {'amount': '487047858', 'precision': 6, 'nai': '@@000000037'}, 'trx_id': '0000000000000000000000000000000000000000', 'block': 42304342, 'trx_in_block': 4294967295, 'op_in_trx': 0, 'virtual_op': 1, 'timestamp': '2020-04-06T13:01:27', 'account': 'themarkymark', 'type': 'producer_reward', '_id': '5efd96c86758e62daab6251b4fd40e286ab6f3c2', 'index': 2411565}
{'producer': 'themarkymark', 'vesting_shares': {'amount': '487047842', 'precision': 6, 'nai': '@@000000037'}, 'trx_id': '0000000000000000000000000000000000000000', 'block': 42304354, 'trx_in_block': 4294967295, 'op_in_trx': 0, 'virtual_op': 1, 'timestamp': '2020-04-06T13:02:03', 'account': 'themarkymark', 'type': 'producer_reward', '_id': 'fa4ff605eaec77ec4949b475fba30f5372c70d69', 'index': 2411566}
{'producer': 'themarkymark', 'vesting_shares': {'amount': '476907066', 'precision': 6, 'nai': '@@000000037'}, 'trx_id': '0000000000000000000000000000000000000000', 'block': 45322425, 'trx_in_block': 4294967295, 'op_in_trx': 0, 'virtual_op': 1, 'timestamp': '2020-07-20T15:27:15', 'account': 'themarkymark', 'type': 'producer_reward', '_id': 'a4409a3b8798fef22a0b3831e0be451433976298', 'index': 2637227}
{'producer': 'themarkymark', 'vesting_shares': {'amount': '476907066', 'precision': 6, 'nai': '@@000000037'}, 'trx_id': '0000000000000000000000000000000000000000', 'block': 45322425, 'trx_in_block': 4294967295, 'op_in_trx': 0, 'virtual_op': 1, 'timestamp': '2020-07-20T15:27:15', 'account': 'themarkymark', 'type': 'producer_reward', '_id': 'a4409a3b8798fef22a0b3831e0be451433976298', 'index': 2637228}
There are not in order. As only one producer_reward is possible per block, these 6 entries are only 3 valid ones.
The duplicate entries can also check directly on the API:
curl -s --data '{"jsonrpc":"2.0", "method":"account_history_api.get_account_history", "params":{"account":"themarkymark", "start":2411566, "limit":3}, "id":1}' https://api.hive.blog