What hashrate you have with webchain?
it should be a little lower than v7
strange rate on webchain. one rig work fine with rate 80-85% from local.
but if add 1-2 rig have lot of rejected duplicate share and rate 40-60%
[2019-01-06 15:11:54] Pool accepted result 0xC80AD1CD [121ms]
[2019-01-06 15:11:54] Pool sent a new job (ID: 96e16412aab5c1865246e58fd67b6cdc)
[2019-01-06 15:11:56] Pool accepted result 0xD4AEDD68 [92ms][ S]
[2019-01-06 15:11:58] Pool sent a new job (ID: 2825b66be399a209ae1f10f5bf4ef5fb)
[2019-01-06 15:12:01] Pool rejected result 0x64858290 (duplicate share)
[2019-01-06 15:12:11] Pool difficulty: 20000
[2019-01-06 15:12:11] Pool sent a new job (ID: f4b8fcf6c5cec6a16d8d1ea973e90ece)
[2019-01-06 15:12:17] Pool sent a new job (ID: 06ca85cfb801ec7bd6ca43e63a1be417)
[2019-01-06 15:12:25] Pool rejected result 0x98A210FA (high rate of invalid shares)
[2019-01-06 15:12:34] Pool difficulty: 20000
[2019-01-06 15:12:34] Pool sent a new job (ID: 06ca85cfb801ec7bd6ca43e63a1be417)
[2019-01-06 15:12:39] Pool sent a new job (ID: 8c6b120b42492e89f9f546388378ec2b)