From Zoom:
Hello,Digital wireless systems can sometimes cause interference at close proximity with the F4, F8, or F8n. The most effective way to resolve this would be to increase the distance between the recorder and the wireless receivers. Some users have suggested using strips of copper tape on top of the device to shield from EMI/RF, or using gaff tape to hold folded strips of blackwrap to the F8. If the interference is coming in through the cable, you could also try using ferrite beads to shield the cable from EMI/RF. We cannot guarantee that these suggestions will eliminate the interference, but they should help in most situations. There have not been changes in shielding in production of the F8/F8n. Let me know if you have any further questions.Sincerely,CUSTOMER SUPPORT
Sounds like more users are likely to have issues. Based on what Larry said, rf experts probably saw this coming. C’est la vie, send it back and keep saving.