First of all don’t use core offsets on 30 series cards for eth, Switch to locked core clocks, as low as you can go without losing hashrate. Should be around 1080mhz on the 3070 and around 1400mhz on the 3060tis, you don’t need power limits with locked core clocks either.
Try trex or gminer instead of phoenix, and if you continue getting invalids after, reduce memory clocks and reboot each time.