Might be too much OC.
Try another miner like T-Rex.
If you get same rejects lower oc.


20200708 06:37:50 kawpow epoch: 174, block: 1309571, period: 436523, diff: 0.337 = 1.60 Gh
20200708 06:38:05 [ OK ] 15219/15246 - 105.73 MH/s, 16ms
20200708 06:38:13 [ OK ] 15220/15247 - 105.74 MH/s, 16ms
20200708 06:38:21 [ OK ] 15221/15248 - 105.76 MH/s, 16ms
20200708 06:38:45 [ OK ] 15222/15249 - 105.85 MH/s, 16ms
20200708 06:38:53 kawpow epoch: 174, block: 1309572, period: 436524, diff: 0.337 = 1.60 Gh
20200708 06:38:58 kawpow epoch: 174, block: 1309573, period: 436524, diff: 0.337 = 1.60 Gh
20200708 06:39:53 [ OK ] 15223/15250 - 105.46 MH/s, 15ms
20200708 06:39:53 GPU #0: RTX 2070 SUPER - 20.88 MH/s, [T:69C, P:138W, F:33%, E:151kH/W]
20200708 06:39:53 GPU #1: RTX 2070 SUPER - 21.71 MH/s, [T:70C, P:139W, F:50%, E:157kH/W]
20200708 06:39:53 GPU #2: RTX 2070 SUPER - 21.28 MH/s, [T:68C, P:138W, F:39%, E:154kH/W]
20200708 06:39:53 GPU #3: RTX 2070 SUPER - 20.99 MH/s, [T:64C, P:139W, F:31%, E:152kH/W]
20200708 06:39:53 GPU #4: RTX 2070 SUPER - 20.59 MH/s, [T:63C, P:138W, F:55%, E:148kH/W]
20200708 06:39:53 Shares/min: 3.448 (Avr. 3.611); total rejected: 0.177%, Avr.Power: 691W, Avr.Efficiency: 153kH/W
20200708 06:39:53 Uptime: 2 days 22 hours 15 mins 25 secs | Algo: kawpow | T-Rex v0.15.8
20200708 06:40:07 [ OK ] 15224/15251 - 105.40 MH/s, 15ms